Citations
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This panel provides information on past usage of this interatomic potential (IP) powered by the OpenKIM Deep Citation framework. The word cloud indicates typical applications of the potential. The bar chart shows citations per year of this IP (bars are divided into articles that used the IP (green) and those that did not (blue)). The complete list of articles that cited this IP is provided below along with the Deep Citation determination on usage. See the Deep Citation documentation for more information.
218 Citations (41 used)
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USED (high confidence) K. Putman, N. Marks, M. Rowles, C. Tomas, J. W. Martin, and I. Suarez-Martinez, “Defining Graphenic Crystallites in Disordered Carbon: Moving Beyond the Platelet Model,” SSRN Electronic Journal. 2022. link Times cited: 7 Abstract: We develop a picture of graphenic crystallites within disord… read moreAbstract: We develop a picture of graphenic crystallites within disordered carbons that goes beyond the traditional model of graphitic platelets at random orientation. Using large atomistic models containing one million atoms, we redefine the meaning of the quantity La extracted from X-ray diffraction (XRD) patterns. Two complementary approaches are used to measure the size of graphenic crystallites, which are defined as regions of regularly arranged hexagons. Firstly, we calculate the X-ray diffraction pattern directly from the atomistic coordinates of the structure and analyse them following a typical experimental process. Second, the graphenic crystallites are identified from a direct geometrical approach. By mapping the structure directly, we replace the idealised picture of the crystallite with a more realistic representation of the material and provide a well-defined interpretation for $L_a$ measurements of disordered carbon. A key insight is that the size distribution is skewed heavily towards small fragments, with more than 75% of crystallites smaller than half of $L_a$. read less USED (high confidence) B. Karasulu, J.-M. Leyssale, P. Rowe, C. R. Weber, and C. de Tomas, “Accelerating the prediction of large carbon clusters via structure search: Evaluation of machine-learning and classical potentials,” Carbon. 2022. link Times cited: 11 USED (high confidence) M. L. Nietiadi, F. Valencia, R. González, E. Bringa, and H. Urbassek, “Collisions between amorphous carbon nanoparticles: phase transformations,” Astronomy & Astrophysics. 2020. link Times cited: 4 Abstract: Context. Collisions of nanoparticles (NPs) occur in dust clo… read moreAbstract: Context. Collisions of nanoparticles (NPs) occur in dust clouds and protoplanetary disks.
Aims. Sticking collisions lead to the growth of NPs, in contrast to bouncing or even fragmentation events and we aim to explore these processes in amorphous carbon NPs.
Methods. Using molecular-dynamics simulations, we studied central collisions between amorphous carbon NPs that had radii in the range of 6.5–20 nm and velocities of 100–3000 m s−1, and with varying sp3 content (20–55%).
Results. We find that the collisions are always sticking. The contact radius formed surpasses the estimate provided by the traditional Johnson-Kendall-Roberts model, pointing at the dominant influence of attractive forces between the NPs. Plasticity occurs via shear-transformation zones. In addition, we find bond rearrangements in the collision zone. Low-sp3 material (sp3 ≤ 40%) is compressed to sp3 > 50%. On the other hand, for the highest sp3 fraction, 55%, graphitization starts in the collision zone leading to low-density and even porous material.
Conclusions. Collisions of amorphous carbon NPs lead to an increased porosity, atomic surface roughness, and changed hybridization that affect the mechanical and optical properties of the collided NPs. read less USED (high confidence) S. Best, J. B. Wasley, C. de Tomas, A. Aghajamali, I. Suarez-Martinez, and N. Marks, “Evidence for Glass Behavior in Amorphous Carbon,” C — Journal of Carbon Research. 2020. link Times cited: 8 Abstract: Amorphous carbons are disordered carbons with densities of c… read moreAbstract: Amorphous carbons are disordered carbons with densities of circa 1.9–3.1 g/cc and a mixture of sp2 and sp3 hybridization. Using molecular dynamics simulations, we simulate diffusion in amorphous carbons at different densities and temperatures to investigate the transition between amorphous carbon and the liquid state. Arrhenius plots of the self-diffusion coefficient clearly demonstrate that there is a glass transition rather than a melting point. We consider five common carbon potentials (Tersoff, REBO-II, AIREBO, ReaxFF and EDIP) and all exhibit a glass transition. Although the glass-transition temperature (Tg) is not significantly affected by density, the choice of potential can vary Tg by up to 40%. Our results suggest that amorphous carbon should be interpreted as a glass rather than a solid. read less USED (high confidence) J. L. Fogg, A. Aghajamali, J. Hinks, S. Donnelly, A. Shiryaev, and N. Marks, “Modification of nanodiamonds by xenon implantation: A molecular dynamics study,” Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 2019. link Times cited: 6 USED (high confidence) G. Opletal, B. Sun, T. Petersen, S. Russo, and A. Barnard, “Vacancy induced formation of nanoporous silicon, carbon and silicon carbide.,” Physical chemistry chemical physics : PCCP. 2019. link Times cited: 6 Abstract: Nanoporous semiconductors are used in a range of application… read moreAbstract: Nanoporous semiconductors are used in a range of applications from sensing and gas separation, to photovoltaics, rechargeable batteries, energetic materials and micro electro mechanical systems. In most cases porosity occurs in conjunction with the competing process of amorphisation, creating a complicated material that responds differently to strain and density changes, depending on the composition. In this paper we use simple computational workflow involving Monte Carlo simulation, numerical characterisation and statistical analysis to explore the development of amorphous and nanoporous carbon, silicon and silicon carbide. We show that amorphous regions in Si and SiC form in advance of nanopores, and are essential in stabilising the nanopores once developed. Carbon prefers a porous structure at lower strains than amorphisation and exhibits a bimodal change in the structure which correlates with the change in C-C bond angles from tetrahedral sp3-like bonds to hexagonal sp2-like bonds as the strain increases. These results highlight how both of these processes can be analysed simultaneously using reliable interatomic forcefields or density functionals, provided sufficient samples are included to support the statistics. read less USED (high confidence) T. Shiell et al., “In situ
analysis of the structural transformation of glassy carbon under compression at room temperature,” Physical Review B. 2019. link Times cited: 17 Abstract: J.E.B. would like to acknowledge the Australian Research Cou… read moreAbstract: J.E.B. would like to acknowledge the Australian Research Council (ARC) for financial support through a Future Fellowship (Grant No. FT130101355). J.E.B. and D.G.M.
acknowledge funding under the ARC Discovery Project
scheme (Grant No. DP140102331). B.H. acknowledges funding through the ORNL Neutron Scattering Facilities, DOE
Office of Science User Facilities operated by the Oak Ridge
National Laboratory. N.A.M. acknowledges financial support
through a fellowship, Grant No. FT120100924. I.S.-M. acknowledges financial support through a fellowship, Grant
No. FT140100191. Work by R.B. was supported by the
Energy Frontier Research in Extreme Environments (EFree)
Center, an Energy Frontier Research Center funded by the
U.S. Department of Energy (DOE), Office of Science, Basic
Energy Sciences (BES) under Award No. DE-SC0001057.
Computational resources are provided by the Pawsey Supercomputing Centre with funding from the Australian
Government and the Government of Western Australia. The
XRD measurements presented here were performed at HP CAT (Sector 16), Advanced Photon Source (APS), Argonne
National Laboratory. HPCAT operations are supported by
DOE-NNSA under Award No. DE-NA0001974, with partial instrumentation funding by NSF. The Advanced Photon
Source is a U.S. Department of Energy (DOE) Office of
Science User Facility operated for the DOE Office of Science
by Argonne National Laboratory under Contract No. DEAC02-06CH11357.
This work has been partially supported by the U.S. Department of Energy. ORNL is managed by UT-Battelle, LLC,
under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy read less USED (high confidence) T. Shiell et al., “Graphitization of Glassy Carbon after Compression at Room Temperature.,” Physical review letters. 2018. link Times cited: 41 Abstract: Glassy carbon is a technologically important material with i… read moreAbstract: Glassy carbon is a technologically important material with isotropic properties that is nongraphitizing up to ∼3000 °C and displays complete or "superelastic" recovery from large compression. The pressure limit of these properties is not yet known. Here we use experiments and modeling to show permanent densification, and preferred orientation occurs in glassy carbon loaded to 45 GPa and above, where 45 GPa represents the limit to the superelastic and nongraphitizing properties of the material. The changes are explained by a transformation from its sp^{2} rich starting structure to a sp^{3} rich phase that reverts to fully sp^{2} bonded oriented graphite during pressure release. read less USED (high confidence) S. Furmaniak, P. A. Gauden, P. Kowalczyk, and A. Patrykiejew, “Monte Carlo study of chemical reaction equilibria in pores of activated carbons,” RSC Advances. 2017. link Times cited: 5 Abstract: This work has presented the results of a rather extensive Mo… read moreAbstract: This work has presented the results of a rather extensive Monte Carlo study concerning the effects of confinement on the reactions taking place in the pores of activated carbons. We have considered here three simple model reactions: isomerisation, dimerisation and synthesis, and investigated how the changes in the carbon porosity, the values of the equilibrium constant, and the energetic parameters of the reacting molecules influence the chemical equilibria. The obtained results show that the main factors affecting the reaction equilibria in pores are the latest ones. When the adsorption energy of the product molecules is higher than that of the reactants, the confinement causes a rise in the reaction yield. In the opposite situation (preferential adsorption of the reactants), the product mole fraction inside the pores is lower than in the bulk phase. It has been shown that the porous structure of activated carbons plays a very important role. The reduction of pore diameters may either increase or decrease the reaction yield, depending on the relative adsorption energy of the reactants and the products. If the product molecules are bigger than the reactant molecules, the presence of pores accessible for the reactant molecules, but inaccessible for the product, causes additional reduction of the reaction yield regardless of the magnitudes of the energetic parameters of the reacting species. read less USED (high confidence) F. Gayk, J. Ehrens, T. Heitmann, P. Vorndamme, A. Mrugalla, and J. Schnack, “Young’s moduli of carbon materials investigated by various classical molecular dynamics schemes,” Physica E-low-dimensional Systems & Nanostructures. 2017. link Times cited: 16 USED (high confidence) S. Furmaniak, A. Terzyk, P. A. Gauden, P. Kowalczyk, and P. Harris, “Folding of graphene slit like pore walls—a simple method of improving CO2 separation from mixtures with CH4 or N2,” Journal of Physics: Condensed Matter. 2014. link Times cited: 9 Abstract: We report for the first time a detailed procedure for creati… read moreAbstract: We report for the first time a detailed procedure for creating a simulation model of energetically stable, folded graphene-like pores and simulation results of CO2/CH4 and CO2/N2 separation using these structures. We show that folding of graphene structures is a very promising method to improve the separation of CO2 from mixtures with CH4 and N2. The separation properties of the analysed materials are compared with carbon nanotubes having similar diameters or S/V ratio. The presented results have potential importance in the field of CO2 capture and sequestration. read less USED (high confidence) S. Furmaniak, A. Terzyk, P. A. Gauden, P. Kowalczyk, and G. Szymański, “Influence of activated carbon surface oxygen functionalities on SO2 physisorption - Simulation and experiment,” Chemical Physics Letters. 2013. link Times cited: 31 USED (high confidence) J. Schall, G. Gao, and J. Harrison, “Effects of Adhesion and Transfer Film Formation on the Tribology of Self-Mated DLC Contacts†,” Journal of Physical Chemistry C. 2010. link Times cited: 139 Abstract: Diamond and diamondlike carbon (DLC) films exhibit a wide ra… read moreAbstract: Diamond and diamondlike carbon (DLC) films exhibit a wide range of sometimes contradictory tribological behavior. Experimentally, isolating the influences of factors such as film structure, testing conditions, and environmental effects has proven difficult. In this work, molecular dynamics simulations were used to examine the effects of film structure, passivation, adhesion, tribochemistry, and load on the tribology of self-mated DLC contacts. Addition of hydrogen to a DLC film causes a large decrease in the unsaturated carbon bonds at the interface of the film when compared to both the bulk and non-hydrogenated films. These unsaturated carbon atoms serve as initiation points for the formation of covalent bonds between the counterface and the film. These adhesive interactions cause an increase in friction during sliding. The formation and breaking of covalent bonds during sliding results in the formation of a transfer film. When covalent bonds break, friction decreases and there is a concomitant increase ... read less USED (high confidence) Y. Kowaki, A. Harada, F. Shimojo, and K. Hoshino, “Radius dependence of the melting temperature of single-walled carbon nanotubes: molecular-dynamics simulations,” Journal of Physics: Condensed Matter. 2007. link Times cited: 20 Abstract: We have investigated the radius dependence of the melting te… read moreAbstract: We have investigated the radius dependence of the melting temperature of single-walled carbon nanotubes (SWCNTs) by classical molecular-dynamics (MD) simulations using the environment-dependent interatomic potential (EDIP) proposed by Marks. Here we define the ‘melting temperature’ as a temperature at which there occurs a thermal instability of SWCNTs. We have carried out molecular-dynamics simulations at several temperatures for carbon nanotubes with various radii and estimated the ‘melting temperature’ based on the temperature dependence of the radial distribution functions, mean-square displacements and atomic configurations. It is shown that the ‘melting temperature’ of SWCNTs decreases with decreasing radius. The origin of this radius dependence of the melting temperature of SWCNTs is discussed in relation to the stability of SWCNTs energetically based on the strain energy of carbon nanotubes. read less USED (low confidence) H. Ramézani, I. Ellien, Z. E. Oufir, N. Mathieu, S. Delpeux, and S. Bhatia, “Clustering of caffeine in water and its adsorption in activated carbon: Molecular simulations and experiments,” Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2023. link Times cited: 0 USED (low confidence) J. Huang, J. Peng, X. Qiu, and X. Li, “Evolution of the Microstructure, Hybridization, and Internal Stress of Al-Doped Diamond-Like Carbon Coatings: A Molecular Dynamics Simulation.,” Langmuir : the ACS journal of surfaces and colloids. 2023. link Times cited: 1 Abstract: This work modified some parameters related to the bond order… read moreAbstract: This work modified some parameters related to the bond order in REBO-II of the C-C interaction and simulated the ta-C:Al film deposition using the large-scale atomic/molecular massively parallel simulator especially focused on the effect of the Al-doping content on the microstructural and mechanical properties of tetrahedral amorphous carbon films. According to the Al existence state, the Al content in the films can be divided into three ranges: range I─under 5 at % Al, a single Al atom or a small cluster with 2-3 Al atoms disperses separately in the matrix; range II─at 5-20 at. % Al, the number and incorporating Al atoms of the clusters increase with the Al content; range III─above 20 at. % Al, only a solid network of aluminum atoms forms, which becomes thickened and densified with Al content increment. The existence states of Al atoms play an essential role in determining mechanical and structural properties. With Al content increasing in the films, the isolated small cluster of atoms evolved into a whole network of aluminum inter-crossing with the C-network. With the evolution of Al existence states, the sp3C fraction decreases monotonically, while the sp2C fraction increases. In range III, the network of aluminum promotes the growth of sp1C sites. The residual compressive stress in the film decreased rapidly with the Al content increasing in range I and II, but it reached a low-level constant value in range III. read less USED (low confidence) A. Rud, I. Kirian, and A. Lakhnik, “Evolution of local atomic arrangements in ball-milled graphite,” Applied Nanoscience. 2022. link Times cited: 2 USED (low confidence) Z. Li et al., “Microstructure changes of diamond and amorphous carbon under shear conditions,” Diamond and Related Materials. 2022. link Times cited: 0 USED (low confidence) G. G. Vidable, R. González, F. Valencia, N. Amigo, D. Tramontina, and E. Bringa, “Simulations of plasticity in diamond nanoparticles showing ultrahigh strength,” Diamond and Related Materials. 2022. link Times cited: 8 USED (low confidence) N. Orekhov, G. Ostroumova, and V. Stegailov, “High temperature pure carbon nanoparticle formation: Validation of AIREBO and ReaxFF reactive molecular dynamics,” Carbon. 2020. link Times cited: 40 USED (low confidence) A. J. McKenna, T. Trevethan, C. D. Latham, P. Young, and M. Heggie, “Threshold displacement energy and damage function in graphite from molecular dynamics,” Carbon. 2016. link Times cited: 44 USED (low confidence) M. Joe, M. Moon, and K.-R. Lee, “Atomistic simulations of diamond-like carbon growth,” Thin Solid Films. 2012. link Times cited: 12 USED (low confidence) D. Huang, J. Pu, Z. Lu, and Q. Xue, “Microstructure and surface roughness of graphite‐like carbon films deposited on silicon substrate by molecular dynamic simulation,” Surface and Interface Analysis. 2012. link Times cited: 14 Abstract: Molecular dynamics simulations are performed on the atomic o… read moreAbstract: Molecular dynamics simulations are performed on the atomic origin of the growth process of graphite‐like carbon film on silicon substrate. The microstructure, mass density, and internal stress of as‐deposited films are investigated systematically. A strong energy dependence of microstructure and stress is revealed by varying the impact energy of the incident atoms (in the range 1–120 eV). As the impact energy is increased, the film internal stress converts from tensile stress to compressive stress, which is in agreement with the experimental results, and the bonding of C‐Si in the film is also increased for more substrate atoms are sputtered into the grown film. At the incident energy 40 eV, a densification of the deposited material is observed and the properties such as density, sp3 fraction, and compressive stress all reach their maximums. In addition, the effect of impact energy on the surface roughness is also studied. The surface morphology of the film exhibits different characteristics with different incident energy. When the energy is low (<40 eV), the surface roughness is reduced with the increasing of incident energy, and it reaches the minimum at 50 eV. Copyright © 2012 John Wiley & Sons, Ltd. read less USED (low confidence) P. Kowalczyk, P. A. Gauden, and A. Terzyk, “Structural properties of amorphous diamond -like carbon: percolation, cluster, and pair correlation analysis,” RSC Advances. 2012. link Times cited: 18 Abstract: A detailed atomistic model of amorphous diamond-like carbon … read moreAbstract: A detailed atomistic model of amorphous diamond-like carbon was developed combining experimental neutron scattering data (K. W. R. Gilkes, P. H. Gaskell and J. Robertson, Phys. Rev. B, 1995, 51, 12303) with the hybrid reverse Monte Carlo method. From the experimentally consistent nanoscale model of the disordered tetrahedral carbon we computed various properties, including: binding energy distribution, neighbor distribution function, bond angle distribution, cluster size distributions for different C–C bond lengths, and percolation threshold. Analysis of microscopic configurations revealed that the network structure of the studied amorphous diamond-like carbon lacks any graphitic fragments (i.e., regular hexagons with a 120° C–C–C bond angle). We found that for the assumed C–C bond length ≤ 1.42 A (i.e., sp2 hybridization), the carbon network is poorly connected with a 70% contribution from isolated carbon atoms. The percolation threshold corresponds to a C–C bond length ≤ 1.52 A, which is close to 1.54 A (i.e., C–C bond length in perfect diamond). This finding is consistent with experimental high levels of tetrahedral bonding (i.e., sp3 hybridization) reported for high density tetrahedral amorphous carbons (i.e., sp3 fraction of 80–85%). Thus, we concluded that the HRMC method complemented with cluster size analysis and determination of percolation threshold is a promising methodology in studies of ill-defined carbonaceous materials. read less USED (low confidence) K. Hoshino, “Structure of liquid metals by ab initio molecular-dynamics simulations,” Journal of Physics: Condensed Matter. 2009. link Times cited: 6 Abstract: How the study of liquid metals has progressed in the past th… read moreAbstract: How the study of liquid metals has progressed in the past three decades is summarized briefly from a personal point of view. It is emphasized that, by ab initio molecular-dynamics (MD) simulations, we can now obtain the electronic states as well as the structure of liquid metals at the same time and therefore we can understand the characteristic features of the microscopic atomic structure and bonding states in real space. As examples we show the results of our ab initio MD simulations for liquid phosphorus, liquid tellurium and liquid carbon at high pressures. read less USED (low confidence) H. Bu, Y. Chen, M. Zou, H. Yi, K. Bi, and Z. Ni, “Atomistic simulations of mechanical properties of graphene nanoribbons,” Physics Letters A. 2009. link Times cited: 145 USED (low confidence) Y. Kowaki, A. Harada, F. Shimojo, and K. Hoshino, “Reconstruction of carbon atoms around a point defect of a graphene: a hybrid quantum/classical molecular-dynamics simulation,” Journal of Physics: Condensed Matter. 2009. link Times cited: 3 Abstract: We have investigated the rearrangement of carbon atoms aroun… read moreAbstract: We have investigated the rearrangement of carbon atoms around a point defect of a graphene using a hybrid ab initio/classical molecular-dynamics (MD) simulation method, in which 36 carbon atoms surrounding a point defect are treated by the ab initio MD method and the other 475 carbon atoms relatively far from the point defect are treated by the classical MD method. We have confirmed a formation of a 5-1DB defect (a pentagon and a dangling bond) from the time dependence of atomic configurations and electron density distributions obtained by our simulation. We have found that the pentagon is formed in two different positions around the point defect, and that the two positions appear alternately during the simulation, the frequency of which increases with increasing temperature. read less USED (low confidence) H. Amara, J. Roussel, C. Bichara, J. Gaspard, and F. Ducastelle, “Tight-binding potential for atomistic simulations of carbon interacting with transition metals: Application to the Ni-C system,” Physical Review B. 2008. link Times cited: 95 Abstract: We present a tight-binding potential for transition metals, … read moreAbstract: We present a tight-binding potential for transition metals, carbon, and transition-metal carbides, which has been optimized through a systematic fitting procedure. A minimal basis, including the s and p electrons of carbon and the d electrons of the transition metal, is used to obtain a transferable tight-binding model of the carbon-carbon, metal-metal, and metal-carbon interactions applicable to binary systems. The Ni-C system is more specifically discussed. The successful validation of the potential for different atomic configurations indicates a good transferability of the model and makes it a good choice for atomistic simulations sampling a large configuration space. This approach appears to be very efficient to describe interactions in systems containing carbon and transition-metal elements. By way of example, we present results concerning the epitaxial growth of graphene sheets on (111) Ni surfaces, as well as the catalytic nucleation of carbon nanotubes. read less USED (low confidence) Q. Lu, N. Marks, G. Schatz, and T. Belytschko, “Nanoscale fracture of tetrahedral amorphous carbon by molecular dynamics: Flaw size insensitivity,” Physical Review B. 2008. link Times cited: 19 Abstract: The fracture of tetrahedral amorphous carbon at the nanoscal… read moreAbstract: The fracture of tetrahedral amorphous carbon at the nanoscale was investigated with molecular dynamics simulations using the environment-dependent interatomic potential. It was found that the fracture strength of amorphous carbon nanospecimens is insensitive to initial cracks with diameters smaller than about $40\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$, i.e., the material exhibits flaw tolerance at the nanoscale. It was also found that amorphous carbon nanospecimens fracture very differently from diamond; (i) failure is gradual instead of catastrophic and (ii) it is accompanied with voidlike defect growth and coalescence. This fracture behavior appears to result from the structural disorder of amorphous carbon. In order to further explore the effect of crack size in materials with structural disorder, larger two-dimensional random network models were studied and found to also exhibit void growth during fracture and flaw tolerance. read less USED (low confidence) A. Harada, F. Shimojo, and K. Hoshino, “Hydrogen desorption from nanostructured graphite: ab initio molecular-dynamics studies,” Journal of Physics: Condensed Matter. 2007. link Times cited: 1 Abstract: We have carried out hybrid ab initio/classical molecular-dyn… read moreAbstract: We have carried out hybrid ab initio/classical molecular-dynamics simulations for the model system of hydrogen-adsorbed nanostructured graphite. We have investigated the effect of the recrystallization of the nanostructured graphite to the bonding states of hydrogen atoms at 1000 K and the desorption mechanism of the hydrogen dimer from the graphite at 2000 K. We have shown that the recrystallization weakens the bond between the hydrogen and the carbon atoms and the desorption of hydrogen atoms, as the hydrogen dimer occurs at 2000 K. read less USED (low confidence) L. Huang and J. Kieffer, “Thermomechanical anomalies and polyamorphism in B 2 O 3 glass: A molecular dynamics simulation study,” Physical Review B. 2006. link Times cited: 61 Abstract: Molecular dynamics MD simulations, based on a new coordinati… read moreAbstract: Molecular dynamics MD simulations, based on a new coordination-dependent charge-transfer potential, were used to study the behavior of B2O3 in response to various thermal and mechanical constraints. This interaction potential allows for the charges on atoms to redistribute upon the formation and rupture of chemical bonds, and dynamically adjusts to multiple coordination states for a given species. Our simulations reveal the structural origin of the anomalous thermomechanical behaviors of B2O3, such as the increase of mechanical moduli upon expansion of the structure. While this phenomenon has been experimentally observed in the glass just below Tg and in the molten state above 800 °C, our simulations predict for the first time that the mechanical moduli of B2O3 glass also increase upon expansion under tensile stress. These anomalous behaviors can be explained as the result of localized structural transformations between two motifs of different stiffness that are similar to those found in the material’s crystalline counterparts. The mechanism we found for B2O3 is analogous to the one we identified earlier as underlying the anomalous behaviors of SiO2, and appears to be universal for network-forming glasses. Furthermore, our simulations led us to the discovery of new low-density B2O3 crystals, which provide a key to understanding the anomalous thermomechanical behaviors of vitreous B2O3 and the crystallization anomaly of this compound. read less USED (low confidence) A. Harada, F. Shimojo, and K. Hoshino, “A Desorption Mechanism of Hydrogen Atoms Adsorbed on A Graphite Layer: Ab initio Molecular-Dynamics Simulations,” Journal of the Physical Society of Japan. 2005. link Times cited: 6 Abstract: We have carried out ab initio molecular-dynamics simulations… read moreAbstract: We have carried out ab initio molecular-dynamics simulations for the model system of hydrogen-adsorbed graphite to investigate the temperature-induced desorption of hydrogen atoms from the graphite... read less USED (low confidence) N. Marks, “Thin film deposition of tetrahedral amorphous carbon: a molecular dynamics study,” Diamond and Related Materials. 2005. link Times cited: 56 USED (low confidence) R. Gago et al., “Evolution of s p 2 networks with substrate temperature in amorphous carbon films: Experiment and theory,” Physical Review B. 2005. link Times cited: 56 Abstract: The evolution of $s{p}^{2}$ hybrids in amorphous carbon (a-C… read moreAbstract: The evolution of $s{p}^{2}$ hybrids in amorphous carbon (a-C) films deposited at different substrate temperatures was studied experimentally and theoretically. The bonding structure of a-C films prepared by filtered cathodic vacuum arc was assessed by the combination of visible Raman spectroscopy, x-ray absorption, and spectroscopic ellipsometry, while a-C structures were generated by molecular-dynamics deposition simulations with the Brenner interatomic potential to determine theoretical $s{p}^{2}$ site distributions. The experimental results show a transition from tetrahedral a-C (ta-C) to $s{p}^{2}$-rich structures at $\ensuremath{\sim}500\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The $s{p}^{2}$ hybrids are mainly arranged in chains or pairs whereas graphitic structures are only promoted for $s{p}^{2}$ fractions above 80%. The theoretical analysis confirms the preferred pairing of isolated $s{p}^{2}$ sites in ta-C, the coalescence of $s{p}^{2}$ clusters for medium $s{p}^{2}$ fractions, and the pronounced formation of rings for $s{p}^{2}$ fractions $g80%$. However, the dominance of sixfold rings is not reproduced theoretically, probably related to the functional form of the interatomic potential used. read less USED (low confidence) A. Harada, F. Shimojo, and K. Hoshino, “Pressure-Induced Structural Change of Liquid Carbon Studied by Ab Initio Molecular-Dynamics Simulations,” Journal of the Physical Society of Japan. 2005. link Times cited: 8 Abstract: We have studied the structural and the electronic properties… read moreAbstract: We have studied the structural and the electronic properties of liquid carbon as a function of the pressure using ab initio molecular-dynamics simulation. We are particularly concerned with the pre... read less USED (low confidence) G. Pearce, N. Marks, D. Mckenzie, and M. Bilek, “Molecular dynamics simulation of the thermal spike in amorphous carbon thin films,” Diamond and Related Materials. 2005. link Times cited: 20 USED (low confidence) C. Mathioudakis, G. Kopidakis, P. Kelires, C. Wang, and K. Ho, “Physical trends in amorphous carbon: A tight-binding molecular-dynamics study,” Physical Review B. 2004. link Times cited: 41 USED (low confidence) N. Marks, J. Bell, G. Pearce, D. Mckenzie, and M. Bilek, “Atomistic simulation of energy and temperature effects in the deposition and implantation of amorphous carbon thin films,” Diamond and Related Materials. 2003. link Times cited: 28 USED (low confidence) F. Valencia et al., “Nanoindentation of Amorphous Carbon: a combined experimental and simulation approach,” Acta Materialia. 2021. link Times cited: 21 USED (low confidence) Q. Lu, N. Marks, and T. Belytschko, “Molecular Dynamics Simulations of the Fracture Mechanism of Tetrahedral Amorphous Carbon.” 2007. link Times cited: 0 USED (low confidence) T. Petersen, I. Yarovsky, I. Snook, D. McCulloch, and G. Opletal, “Microstructure of an industrial char by diffraction techniques and Reverse Monte Carlo modelling,” Carbon. 2004. link Times cited: 53 NOT USED (low confidence) H. G. Hackbarth et al., “Uncovering atomic-scale polymer-to-ceramic transformations in SiC polymer derived ceramics from polycarbosilanes,” Journal of the European Ceramic Society. 2023. link Times cited: 0 NOT USED (low confidence) F. Vallejos-Burgos et al., “3D nanostructure prediction of porous carbons via gas adsorption,” Carbon. 2023. link Times cited: 0 NOT USED (low confidence) J. W. Martin et al., “Graphite rapidly forms via annihilation of screw dislocations,” Carbon. 2023. link Times cited: 1 NOT USED (low confidence) P. Wang, D. Zhou, H. Zhao, Y. Lin, A. Nie, and H. Wang, “Dislocation-mediated brittle-ductile transition of diamond under high pressure,” Diamond and Related Materials. 2023. link Times cited: 0 NOT USED (low confidence) G. R. Francas, J. W. Martin, I. Suarez-Martinez, and N. Marks, “Topological defects and anisotropic development during pre-graphitization,” Carbon. 2023. link Times cited: 0 NOT USED (low confidence) D. Castillo-Castro et al., “Nanoporous Amorphous Carbon with Exceptional Ultra-High Strength,” Nanomaterials. 2023. link Times cited: 0 Abstract: Nanoporous materials show a promising combination of mechani… read moreAbstract: Nanoporous materials show a promising combination of mechanical properties in terms of their relative density; while there are numerous studies based on metallic nanoporous materials, here we focus on amorphous carbon with a bicontinuous nanoporous structure as an alternative to control the mechanical properties for the function of filament composition.Using atomistic simulations, we study the mechanical response of nanoporous amorphous carbon with 50% porosity, with sp3 content ranging from 10% to 50%. Our results show an unusually high strength between 10 and 20 GPa as a function of the %sp3 content. We present an analytical analysis derived from the Gibson–Ashby model for porous solids, and from the He and Thorpe theory for covalent solids to describe Young’s modulus and yield strength scaling laws extremely well, revealing also that the high strength is mainly due to the presence of sp3 bonding. Alternatively, we also find two distinct fracture modes: for low %sp3 samples, we observe a ductile-type behavior, while high %sp3 leads to brittle-type behavior due to high high shear strain clusters driving the carbon bond breaking that finally promotes the filament fracture. All in all, nanoporous amorphous carbon with bicontinuous structure is presented as a lightweight material with a tunable elasto-plastic response in terms of porosity and sp3 bonding, resulting in a material with a broad range of possible combinations of mechanical properties. read less NOT USED (low confidence) K. Duan et al., “Gradient evolution in graphene reinforced carbon/carbon composites,” Carbon. 2023. link Times cited: 1 NOT USED (low confidence) J. Li, C. Peng, J. Wang, J. Li, and H.-liang Zhang, “Towards an atomistic understanding of hard carbon electrode materials and sodium behaviors,” Diamond and Related Materials. 2022. link Times cited: 0 NOT USED (low confidence) M. A. Caro, “Machine learning based modeling of disordered elemental semiconductors: understanding the atomic structure of a-Si and a-C,” Semiconductor Science and Technology. 2022. link Times cited: 1 Abstract: Disordered elemental semiconductors, most notably a-C and a-… read moreAbstract: Disordered elemental semiconductors, most notably a-C and a-Si, are ubiquitous in a myriad of different applications. These exploit their unique mechanical and electronic properties. In the past couple of decades, density functional theory (DFT) and other quantum mechanics-based computational simulation techniques have been successful at delivering a detailed understanding of the atomic and electronic structure of crystalline semiconductors. Unfortunately, the complex structure of disordered semiconductors sets the time and length scales required for DFT simulation of these materials out of reach. In recent years, machine learning (ML) approaches to atomistic modeling have been developed that provide an accurate approximation of the DFT potential energy surface for a small fraction of the computational time. These ML approaches have now reached maturity and are starting to deliver the first conclusive insights into some of the missing details surrounding the intricate atomic structure of disordered semiconductors. In this Topical Review we give a brief introduction to ML atomistic modeling and its application to amorphous semiconductors. We then take a look at how ML simulations have been used to improve our current understanding of the atomic structure of a-C and a-Si. read less NOT USED (low confidence) C. Ugwumadu et al., “Simulation of Multi-Shell Fullerenes Using Machine-Learning Gaussian Approximation Potential,” SSRN Electronic Journal. 2022. link Times cited: 5 NOT USED (low confidence) N. J. Corrente, E. L. Hinks, A. Kasera, R. Gough, P. Ravikovitch, and A. Neimark, “Modeling adsorption of simple fluids and hydrocarbons on nanoporous carbons,” Carbon. 2022. link Times cited: 2 NOT USED (low confidence) L. Galiakhmetova, I. Pavlov, A. Bayazitov, I. Kosarev, and S. Dmitriev, “Mechanical Properties of Cubene Crystals,” Materials. 2022. link Times cited: 5 Abstract: The fullerene family, whose most popular members are the sph… read moreAbstract: The fullerene family, whose most popular members are the spherical C60 and C70 molecules, has recently added a new member, the cube-shaped carbon molecule C8 called a cubene. A molecular crystal based on fullerenes is called fullerite. In this work, based on relaxational molecular dynamics, two fullerites based on cubenes are described for the first time, one of which belongs to the cubic system, and the other to the triclinic system. Potential energy per atom, elastic constants, and mechanical stress components are calculated as functions of lattice strain. It has been established that the cubic cubene crystal is metastable, while the triclinic crystal is presumably the crystalline phase in the ground state (the potential energies per atom for these two structures are −0.0452 and −0.0480 eV, respectively).The cubic phase has a lower density than the monoclinic one (volumes per cubene are 101 and 97.7 Å3). The elastic constants for the monoclinic phase are approximately 4% higher than those for the cubic phase. The presented results are the first step in studying the physical and mechanical properties of C8 fullerite, which may have potential for hydrogen storage and other applications. In the future, the influence of temperature on the properties of cubenes will be analyzed. read less NOT USED (low confidence) L. Vieira, “A review on the use of glassy carbon in advanced technological applications,” Carbon. 2022. link Times cited: 25 NOT USED (low confidence) Z. E. Oufir, H. Ramézani, N. Mathieu, and S. Delpeux, “Impact of adsorbent carbons and carbon surface conductivity on adsorption capacity of CO2, CH4, N2 and gas separation,” Computational Materials Science. 2021. link Times cited: 8 NOT USED (low confidence) F. Vuković and T. Walsh, “Practical atomistic models of carbon fiber surfaces with tuneable topology and topography,” Composites Science and Technology. 2021. link Times cited: 6 NOT USED (low confidence) Z. E. Oufir, H. Ramézani, N. Mathieu, S. Delpeux, and S. Bhatia, “Influence of force field used in carbon nanostructure reconstruction on simulated phenol adsorption isotherms in aqueous medium,” Journal of Molecular Liquids. 2021. link Times cited: 2 NOT USED (low confidence) A. Aghajamali and A. Karton, “Can force fields developed for carbon nanomaterials describe the isomerization energies of fullerenes,” Chemical Physics Letters. 2021. link Times cited: 8 NOT USED (low confidence) F. Thiemann, P. Rowe, A. Zen, E. A. Müller, and A. Michaelides, “Defect-Dependent Corrugation in Graphene.,” Nano letters. 2021. link Times cited: 20 Abstract: Graphene's intrinsically corrugated and wrinkled topolo… read moreAbstract: Graphene's intrinsically corrugated and wrinkled topology fundamentally influences its electronic, mechanical, and chemical properties. Experimental techniques allow the manipulation of pristine graphene and the controlled production of defects which allows one to control the atomic out-of-plane fluctuations and thus tune graphene's properties. Here, we perform large scale machine learning-driven molecular dynamics simulations to understand the impact of defects on the structure of graphene. We find that defects cause significantly higher corrugation leading to a strongly wrinkled surface. The magnitude of this structural transformation strongly depends on the defect concentration and specific type of defect. Analyzing the atomic neighborhood of the defects reveals that the extent of these morphological changes depends on the preferred geometrical orientation and the interactions between defects. While our work highlights that defects can strongly affect graphene's morphology, it also emphasizes the differences between distinct types by linking the global structure to the local environment of the defects. read less NOT USED (low confidence) Y.-C. Wang, Y. Zhu, and H. Wu, “Formation and topological structure of three-dimensional disordered graphene networks.,” Physical chemistry chemical physics : PCCP. 2021. link Times cited: 7 Abstract: Disordered graphene networks (DGNs) can be regarded as the t… read moreAbstract: Disordered graphene networks (DGNs) can be regarded as the three-dimensional (3D) assembly of graphene-like fragments at the nanoscale, in which some intrinsic topological features are usually hidden in these formless fragments without clear understanding. Although some high-resolution structural patterns have been observed in pyrolytic carbons and flash graphene experimentally, it is still hard to characterize the topology and texture of DGNs considering continuous 3D connectivity. Toward this end, starting from the annealing process, we herein performed molecular dynamics simulations to investigate the formation and topological structure of DGNs. Three typical stages are found during the formation of DGNs, that is, the formation of polyaromatic fragments, formation of a disordered framework, and further graphitization. The topology of the obtained DGNs was then investigated, including topological defects, stacking behavior, and global curvature. Several typical in-plane and out-of-plane topological defects are found to connect the 3D network of graphene-like layers. The computed X-ray diffraction and angular defects demonstrate that a high-density DGN tends to form a randomly stacked structure with more connections, while a low-density DGN exhibits more bowl-shaped layers and a less distorted curvature. At low annealing temperatures, the local curvature of DGNs is highly distorted, and the structure seems to lack graphitization compared to high-temperature ones. read less NOT USED (low confidence) T. Shiell, D. McCulloch, J. Bradby, B. Haberl, and D. Mckenzie, “Neutron diffraction discriminates between models for the nanoarchitecture of graphene sheets in glassy carbon,” Journal of Non-crystalline Solids. 2021. link Times cited: 7 NOT USED (low confidence) Y. Bu, P. Wang, A. Nie, and H. Wang, “Room-temperature plasticity in diamond,” Science China Technological Sciences. 2021. link Times cited: 9 NOT USED (low confidence) Q. Liu, L. Li, Y. Jeng, G. Zhang, C. Shuai, and X. Zhu, “Effect of interatomic potentials on modeling the nanostructure of amorphous carbon by liquid quenching method,” Computational Materials Science. 2020. link Times cited: 9 NOT USED (low confidence) P. Kowalczyk et al., “Atomic-scale molecular models of oxidized activated carbon fibre nanoregions: Examining the effects of oxygen functionalities on wet formaldehyde adsorption,” Carbon. 2020. link Times cited: 19 NOT USED (low confidence) T. C. Sagar, V. Chinthapenta, and M. Horstemeyer, “Effect of defect guided out-of-plane deformations on the mechanical properties of graphene,” Fullerenes, Nanotubes and Carbon Nanostructures. 2020. link Times cited: 5 Abstract: In this paper, nanoscale mechanical properties and failure b… read moreAbstract: In this paper, nanoscale mechanical properties and failure behavior of graphene with Stone-Wales defect concentration were investigated using molecular dynamics simulations with the latest ReaxFFC-2013 potential that can accurately capture bond breakages of graphitic compounds. The choice of interatomic potential plays an essential role in capturing the deformation mechanism accurately. Stable configuration of two-dimensional graphene experiences out-of-plane deformation leading to ripples and wrinkles in graphene. It is observed that the mechanical properties such as Young’s modulus, ultimate tensile strength, and the fracture strain are dependent on the out-of-plane deformation, temperature, defect concentration, defect orientation, defect layout and loading configuration. It is observed that the post transient phase non-homogenous ripples and wrinkles influence the mechanical properties at low and high defect concentrations, respectively. read less NOT USED (low confidence) Y. Bu, P. Wang, A. Nie, and H. Wang, “Room-temperature plasticity in diamond,” Science China Technological Sciences. 2020. link Times cited: 0 NOT USED (low confidence) G. Tripathi, J. Ludwick, M. Cahay, and K. Jensen, “Spatial dependence of the temperature profile along a carbon nanotube during thermal-field emission,” Journal of Applied Physics. 2020. link Times cited: 10 Abstract: An efficient algorithm is described to calculate the spatial… read moreAbstract: An efficient algorithm is described to calculate the spatial dependence of the temperature distribution along a carbon nanotube (CNT) during field emission (FE). The algorithm considers the effects of Joule heating in the CNT and radiative losses from the CNT sidewall and tip. The CNT emission current density and the rate of heat exchange per unit area at the CNT tip due to either Henderson-cooling or Nottingham-heating effects are calculated using recent analytical expressions derived by Jensen [J. Appl. Phys. 126, 065302 (2019)]. The latter are valid in the thermionic and field emission regimes and in the transition region between these two extremes. The temperature dependence of the electrical resistivity ρ ( T ) and the thermal conductivity κ ( T ) of the CNT is also included in the model. It is shown that replacing ρ ( T ) and κ ( T ) by their spatial averages over the length of the CNT can lead to an overestimate of the value of the external electric field threshold at which thermal runaway of the CNT occurs. These results should be considered when calculating the field emission characteristics of CNT arrays such as from a carbon nanotube fiber whose FE properties are primarily determined by the FE properties of the array of CNTs at the tip of the fiber. Using the new algorithm, the simulation times to calculate the CNT FE characteristics and the spatial temperature distribution are found to be nearly two orders of magnitude faster compared to those required when both the current and energy exchange at the CNT tip are calculated numerically. read less NOT USED (low confidence) A. Aghajamali, A. Shiryaev, and N. Marks, “Molecular Dynamics Approach for Predicting Release Temperatures of Noble Gases in Presolar Nanodiamonds,” The Astrophysical Journal. 2020. link Times cited: 2 Abstract: Presolar meteoritic nanodiamond grains carry an array of iso… read moreAbstract: Presolar meteoritic nanodiamond grains carry an array of isotopically distinct noble gas components and provide information on the history of nucleosynthesis, galactic mixing, and the formation of the solar system. In this paper, we develop a molecular dynamics approach to predict the thermal release pattern of implanted noble gases (He and Xe) in nanodiamonds. We provide atomistic details of the unimodal temperature release distribution for He and a bimodal behavior for Xe. Intriguingly, our model shows that the thermal release process of noble gases is highly sensitive to the impact and annealing parameters, as well as the position of the implanted ion in the crystal lattice and morphology of the nanograin. In addition, the model elegantly explains the unimodal and bimodal patterns of noble gas release via the interstitial and substitutional types of defects formed. In summary, our simulations confirm that low-energy ion implantation is a viable way to incorporate noble gases into nanodiamonds, and we provide an explanation of the experimentally observed peculiarities of gas release. read less NOT USED (low confidence) S. Zhu, X. Yan, J. Liu, A. Oganov, and Q. Zhu, “Old Story New Tell: The Graphite to Diamond Transition Revisited,” Chemical Engineering (Engineering) eJournal. 2020. link Times cited: 9 NOT USED (low confidence) E. M. El‐Fawal, L. Saad, and Y. Moustafa, “Computational DFT study of magnetite/graphene oxide nanoadsorbent: Interfacial chemical behavior and remediation performance of heavy metal hydrates from aqueous system,” Water Environment Research. 2020. link Times cited: 13 Abstract: Herein, magnetite/graphene oxide hybrid (MGO) was facilely s… read moreAbstract: Herein, magnetite/graphene oxide hybrid (MGO) was facilely synthesized and analyzed by various techniques such as X‐ray diffraction spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, Brunauer, Emmett, and Teller surface area analyzer, and Raman spectroscopy. A computational density functional theory (DFT) has been applied for the first time to determine the removal mechanism of zinc (Zn2+), nickel (Ni2+), and chromium (Cr6+) hydrates onto the prepared MGO. The adsorption binding energy and geometries of the metal hydrates with oxygen functional group (i.e., hydroxyl, epoxide, carboxylic, carbonyl groups, and magnetite on the MGO surface) were estimated. The complexes configurations comprised via sitting the metal ion perpendicular and above the MGO surface. The zinc hydrate portended to bind more strongly than Ni2+ and Cr6+. Zinc hydrate is favorable to coordinate with hydroxyl and carboxylic group than the other functional groups. The pseudo‐second‐order kinetic and Langmuir isotherm models are well convenient for kinetics and isotherm sorption process, respectively. The results determined that the sorption of heavy metals by nanostructure MGO was observed in the following order: zinc > nickel > chromium as revealed by the DFT computations. The maximum adsorption capacity of Zn2+, Ni2+, and Cr6+ was 333, 250, and 200 mg/g, respectively. Thermodynamic constants depicted that the sorption process is naturally instantaneous and exothermic. The calculated predicted results are fitted with the experimental results. read less NOT USED (low confidence) H. Nguyen, “Graphene layer of hybrid graphene/hexagonal boron nitride model upon heating,” Carbon Letters. 2019. link Times cited: 9 NOT USED (low confidence) W. Ge, Q. Chang, C. Li, and J. Wang, “Multiscale structures in particle–fluid systems: Characterization, modeling, and simulation,” Chemical Engineering Science. 2019. link Times cited: 76 NOT USED (low confidence) M. Bonnin, C. Falvo, F. Calvo, T. Pino, and P. Parneix, “Simulating the structural diversity of carbon clusters across the planar-to-fullerene transition,” Physical Review A. 2019. link Times cited: 9 Abstract: Together with the second generation REBO reactive potential,… read moreAbstract: Together with the second generation REBO reactive potential, replica-exchange molecular dynamics simulations coupled with systematic quenching were used to generate a broad set of isomers for neutral C$_n$ clusters with $n=24$, 42, and 60. All the minima were sorted in energy and analyzed using order parameters to monitor the evolution of their structural and chemical properties. The structural diversity measured by the fluctuations in these various indicators is found to increase significantly with energy, the number of carbon rings, especially 6-membered, exhibiting a monotonic decrease in favor of low-coordinated chains and branched structures. A systematic statistical analysis between the various parameters indicates that energetic stability is mainly driven by the amount of sp$^2$ hybridization, more than any geometrical parameter. The astrophysical relevance of these results is discussed in the light of the recent detection of C$_{60}$ and C$_{60}^+$ fullerenes in the interstellar medium. read less NOT USED (low confidence) H. Nguyen and T. T. Hanh, “Melting process of zigzag boron nitride nanoribbon,” Physica E: Low-dimensional Systems and Nanostructures. 2019. link Times cited: 4 NOT USED (low confidence) F. Vuković, J.-M. Leyssale, P. Aurel, and N. Marks, “Evolution of Threshold Displacement Energy in Irradiated Graphite,” Physical Review Applied. 2018. link Times cited: 14 Abstract: HAL is a multi-disciplinary open access archive for the depo… read moreAbstract: HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Evolution of Threshold Displacement Energy with Dose Studied by Molecular Dynamics Simulations on Irradiated Graphite Models Filip Vukovic, Nigel A Marks, Philippe Aurel, Jean Marc Leyssale read less NOT USED (low confidence) G. Opletal, T. Petersen, S. Russo, and A. Barnard, “PorosityPlus: characterisation of defective, nanoporous and amorphous materials,” Journal of Physics: Materials. 2018. link Times cited: 11 Abstract: As both porous and amorphous semiconductors have different a… read moreAbstract: As both porous and amorphous semiconductors have different advantages the challenge becomes knowing how to select one over the other, and knowing how to anticipate the degree of crystallinity or the fraction of voids as a function of a controllable feature such as the density. These sorts of relationships can be modelled computationally but unambiguous characterisation of the porosity of complex and disordered structures requires specialist tools. In this paper we demonstrate the use of PorosityPlus to investigate porosity in the vacancy induced amorphisation of defective crystals of carbon, silicon and germanium. The PorosityPlus software allows for the identification of vacancies, twin vacancies and larger pores, along with their relative locations and their respective populations. Void migration and coalescence along with the associated density changes can also be calculated. We show that, with increasing initial vacancies (reduced density) carbon (diamond), silicon and germanium exhibit characteristic density-dependent porosity profiles, coupled with simultaneous amorphisation. This is an ideal tool for integration into advanced computational workflows, such as creating fingerprints for topological data analysis or machine learning, since the porosity profile for each configuration is unique. read less NOT USED (low confidence) P. Kowalczyk, D. Parsons, A. Terzyk, P. A. Gauden, and S. Furmaniak, “Cubic Carbon Polymorphs,” Carbon Nanomaterials Sourcebook. 2018. link Times cited: 0 Abstract: The Carbon Nanomaterials Sourcebook contains extensive, inte… read moreAbstract: The Carbon Nanomaterials Sourcebook contains extensive, interdisciplinary coverage of carbon nanomaterials, encompassing the full scope of the field—from physics, chemistry, and materials science to molecular biology, engineering, and medicine—in two comprehensive volumes. Written in a tutorial style, this second volume of the sourcebook: • Focuses on nanoparticles, nanocapsules, nanofibers, nanoporous structures, and nanocomposites • Describes the fundamental properties, growth mechanisms, and processing of each nanomaterial discussed • Explores functionalization for electronic, energy, biomedical, and environmental applications • Showcases materials with exceptional properties, synthesis methods, large-scale production techniques, and application prospects • Provides the tools necessary for understanding current and future technology developments, including important equations, tables, and graphs Each chapter is dedicated to a different type of carbon nanomaterial and addresses three main areas: formation, properties, and applications. This setup allows for quick and easy search, making the Carbon Nanomaterials Sourcebook: Nanoparticles, Nanocapsules, Nanofibers, Nanoporous Structures, and Nanocomposites, Volume II a must-have reference for scientists and engineers. read less NOT USED (low confidence) C. Tomas, I. Suarez-Martinez, and N. Marks, “Carbide-derived carbons for dense and tunable 3D graphene networks,” Applied Physics Letters. 2018. link Times cited: 23 Abstract: The mechanical properties of carbide-derived carbons (CDCs) … read moreAbstract: The mechanical properties of carbide-derived carbons (CDCs) are computed using molecular dynamics simulations, spanning the experimental density range and synthesis temperatures. The structures consist of nanoporous networks with continuous graphene walls enclosing the pores. Calculation of elastic constants and simulation of tensile strain reveal a direct relationship between the microstructure and elasticity, with the density and temperature inducing significant changes in the pore topology and medium-range order. CDCs have a high elastic moduli and high ultimate tensile strengths while showing resistance to brittle fracture. This suggests that CDCs are a promising route to achieve dense 3D graphene networks with tunable mechanical properties.The mechanical properties of carbide-derived carbons (CDCs) are computed using molecular dynamics simulations, spanning the experimental density range and synthesis temperatures. The structures consist of nanoporous networks with continuous graphene walls enclosing the pores. Calculation of elastic constants and simulation of tensile strain reveal a direct relationship between the microstructure and elasticity, with the density and temperature inducing significant changes in the pore topology and medium-range order. CDCs have a high elastic moduli and high ultimate tensile strengths while showing resistance to brittle fracture. This suggests that CDCs are a promising route to achieve dense 3D graphene networks with tunable mechanical properties. read less NOT USED (low confidence) E. Piña-Salazar et al., “Water Adsorption Property of Hierarchically Nanoporous Detonation Nanodiamonds.,” Langmuir : the ACS journal of surfaces and colloids. 2017. link Times cited: 24 Abstract: The detonation nanodiamonds form the aggregate having interp… read moreAbstract: The detonation nanodiamonds form the aggregate having interparticle voids, giving a marked hygroscopic property. As the relationship between pore structure and water adsorption of aggregated nanodiamonds is not well understood yet, adsorption isotherms of N2 at 77 K and of water vapor at 298 K of the well-characterized aggregated nanodiamonds were measured. HR-TEM and X-ray diffraction showed that the nanodiamonds were highly crystalline and their average crystallite size was 4.5 nm. The presence of the graphitic layers on the nanodiamond particle surface was confirmed by the EELS examination. The pore size distribution analysis showed that nanodiamonds had a few ultramicropores with predominant mesopores of 4.5 nm in average size. The water vapor adsorption isotherm of IUPAC Type V indicates the hydrophobicity of the nanodiamond aggregates, with the presence of hydrophilic sites. Then the hygroscopic nature of nanodiamonds should be associated with the surface functionalities of the graphitic shell and the ultramicropores on the mesopore walls. read less NOT USED (low confidence) C. Tomas, I. Suarez-Martinez, F. Vallejos-Burgos, M. J. López, K. Kaneko, and N. Marks, “Structural prediction of graphitization and porosity in carbide-derived carbons,” Carbon. 2017. link Times cited: 58 NOT USED (low confidence) Y. Xie, X.-jie Zhang, and Z. Liu, “Graphite to Diamond: Origin for Kinetics Selectivity.,” Journal of the American Chemical Society. 2017. link Times cited: 46 Abstract: Under mild static compression (15 GPa), graphite preferentia… read moreAbstract: Under mild static compression (15 GPa), graphite preferentially turns into hexagonal diamond, not cubic diamond, the selectivity of which is against thermodynamics. Here we, via novel potential energy surface global exploration, report seven types low energy intermediate structures at the atomic level that are key to the kinetics of graphite to diamond solid phase transition. On the basis of quantitative kinetics data, we show that hexagonal diamond has a facile initial nucleation mechanism inside graphite matrix and faster propagation kinetics owing to the presence of three coherent graphite/hexagonal diamond interfaces, forming coherent nuclei in graphite matrix. By contrast, for the lack of coherent nucleus core, the growth of cubic diamond is at least 40 times slower and its growth is inevitably mixing with that of hexagonal diamond. read less NOT USED (low confidence) K. Vimalanathan et al., “Fluid dynamic lateral slicing of high tensile strength carbon nanotubes,” Scientific Reports. 2016. link Times cited: 49 NOT USED (low confidence) F. Memarian, A. Fereidoon, and M. Ganji, “Graphene Young’s modulus: Molecular mechanics and DFT treatments,” Superlattices and Microstructures. 2015. link Times cited: 90 NOT USED (low confidence) S. Furmaniak, S. Koter, A. Terzyk, P. A. Gauden, P. Kowalczyk, and G. Rychlicki, “New insights into the ideal adsorbed solution theory.,” Physical chemistry chemical physics : PCCP. 2015. link Times cited: 23 Abstract: The GCMC technique is used for simulation of adsorption of C… read moreAbstract: The GCMC technique is used for simulation of adsorption of CO2-CH4, CO2-N2 and CH4-N2 mixtures (at 298 K) on six porous carbon models. Next we formulate a new condition of the IAS concept application, showing that our simulated data obey this condition. Calculated deviations between IAS predictions and simulation results increase with the rise in pressure as in the real experiment. For the weakly adsorbed mixture component the deviation from IAS predictions is higher, especially when its content in the gas mixture is low, and this is in agreement with the experimental data. Calculated activity coefficients have similar plots to deviations between IAS and simulations, moreover obtained from simulated data activity coefficients are similar qualitatively as well as quantitatively to experimental data. Since the physical interpretation of activity coefficients is completely lacking we show for the first time that they can be described by the formulas derived from the expression for G(ex) for the ternary mixture. Finally we also for the first time show the linear relationship between the chemical potentials of nonideal and ideal solutions and the reduced temperature of interacting mixture components, and it is proved that the deviation from ideality is larger if adsorption occurs in a more microporous system. read less NOT USED (low confidence) S. Furmaniak, “Influence of activated carbon porosity and surface oxygen functionalities’ presence on adsorption of acetonitrile as a simple polar volatile organic compound,” Environmental Technology. 2015. link Times cited: 18 Abstract: Based on series of porous carbon models, systematic Monte Ca… read moreAbstract: Based on series of porous carbon models, systematic Monte Carlo studies on the adsorption of acetonitrile (as a simple representative of polar volatile organic compounds) were performed. The influence of porosity and chemical composition of the carbon surface on CH3CN adsorption was studied and it was shown that both the factors influenced the adsorption mechanism. A decrease in the pore size and the introduction of oxygen surface groups led to a rise in adsorption energy and to an increase in the filling of accessible volume in the low-pressure part of the isotherm. However, from a practical point of view, it is easier to increase the adsorption by introducing polar groups on the carbon surface than by modifying the porosity. read less NOT USED (low confidence) M. Robinson and N. Marks, “NanoCap: A framework for generating capped carbon nanotubes and fullerenes,” Comput. Phys. Commun. 2014. link Times cited: 21 NOT USED (low confidence) A. Sorkin and H. Su, “Phase diagram of solid-phase transformation in amorphous carbon nanorods.,” The journal of physical chemistry. A. 2014. link Times cited: 4 Abstract: The transformations of amorphous carbon nanorods with differ… read moreAbstract: The transformations of amorphous carbon nanorods with different diameters and densities upon heating up to different temperatures are studied with density-functional-based tight-binding molecular dynamics. Phase diagrams with assorted transformed sp(2) nanostructures depending on both temperatures and line density, under different heating treatments, are presented to place the observations in perspective. Under instant heating, the lowest line density at which a carbon nanotube can form is 8 Å(-1), while a double-walled carbon nanotube can form at a linear density of 19-20 Å(-1) and higher. Under gradual heating, both partially unzipped carbon nanotubes and carbon nanoscrolls are formed as notable intermediate structural motifs. This work sheds light on the microscopic mechanism of various sp(2) nanostructural formations with the featured motifs highlighted as important intermediates, which will serve as an important guide in producing graphene nanoribbons, single-walled and double-walled carbon nanotubes, and carbon nanoscrolls from amorphous carbon nanorods. read less NOT USED (low confidence) P. Kowalczyk et al., “Carbon Molecular Sieves: Reconstruction of Atomistic Structural Models with Experimental Constraints,” Journal of Physical Chemistry C. 2014. link Times cited: 17 Abstract: We propose a novel methodology for developing experimentally… read moreAbstract: We propose a novel methodology for developing experimentally informed structural models of disordered carbon molecular sieves. The hybrid reverse Monte Carlo simulation method coupled with wide-angle X-ray scattering experiments is used for constructing an atomistic level model of a representative sample of carbon molecular sieve film (CMS-F) synthesized in our laboratory. We found that CMS-F possesses a disordered matrix enriched with bended carbon chains and various carbon clusters as opposed to the turbostratic carbon or graphite-like microcrystals. The pore structure of CMS-F has a defected lamellar morphology of one-dimensional periodicity with narrow (∼0.4 nm) micropores. The model is applied to study adsorption properties of CMS-F with respect to adsorbates of practical interest, such as N2, H2, CO, and C6H6. Special attention is paid to the phase transformations in the course of adsorption. In particular, we show theoretically and confirm experimentally that nitrogen solidifies within CMS-F pores ... read less NOT USED (low confidence) S. Furmaniak, A. Terzyk, K. Kaneko, P. A. Gauden, P. Kowalczyk, and T. Ohba, “Surface to volume ratio of carbon nanohorn – A crucial factor in CO2/CH4 mixture separation,” Chemical Physics Letters. 2014. link Times cited: 7 NOT USED (low confidence) Y. Liu, G. F. Zhou, L. He, and H. Ye, “Studying the rotation induced super-lattices on graphite using a type-criterion potential based molecular dynamics method,” Computational Materials Science. 2014. link Times cited: 0 NOT USED (low confidence) A. Rud and I. Kiryan, “Quantitative analysis of the local atomic structure in disordered carbon,” Journal of Non-crystalline Solids. 2014. link Times cited: 12 NOT USED (low confidence) L. Li, M. Xu, W. Song, A. Ovcharenko, G. Zhang, and D. Jia, “The effect of empirical potential functions on modeling of amorphous carbon using molecular dynamics method,” Applied Surface Science. 2013. link Times cited: 55 NOT USED (low confidence) S. Furmaniak, A. Terzyk, P. Kowalczyk, K. Kaneko, and P. A. Gauden, “Separation of CO2-CH4 mixtures on defective single walled carbon nanohorns–tip does matter.,” Physical chemistry chemical physics : PCCP. 2013. link Times cited: 13 Abstract: Using realistic models of single-walled carbon nanohorns and… read moreAbstract: Using realistic models of single-walled carbon nanohorns and their single-walled carbon nanotube counterparts, we study the equilibrium separation of CO2-CH4 mixtures near ambient operating conditions by using molecular simulations. We show that regardless of the studied operating conditions (i.e., total CO2-CH4 mixture pressures and mole fractions of mixture components in the bulk phase), single-walled carbon nanohorns maximize the CO2-CH4 equilibrium separation factor. Optimized samples of single-walled carbon nanohorns consisting of narrow tubular parts capped with horn-shaped tips show highly selective adsorption of CO2 over the CH4 mixture component, with the CO2-CH4 equilibrium separation factor of ~8-12. A large surface-to-volume ratio (i.e., enhanced surface forces) and unique defective morphology (i.e., packing of adsorbed molecules in quasi-one/quasi-zero dimensional nanospaces) of single-walled carbon nanohorns are their key structural properties responsible for the excellent separation performance. Our theoretical simulation results are in quantitative agreement with a recent experimental/theoretical study of the CO2-CH4 adsorption and separation on oxidized single-walled carbon nanohorns [Ohba et al., Chem. Lett., 40, 2011, 1089]. Both experiment and theory showed that the CO2-CH4 equilibrium separation factor of oxidized samples of single-walled nanohorns measured near ambient operating conditions is ~2-5. This reduction in the separation efficiency as compared to optimized samples of single-walled carbon nanohorns is theoretically justified by their lower surface-to-volume ratio (i.e., larger diameters of tubular parts and horn-shaped tips). read less NOT USED (low confidence) X. Mi and Y. Shi, “Topological defects in nanoporous carbon,” Carbon. 2013. link Times cited: 8 NOT USED (low confidence) Z. Sha, P. S. Branicio, Q. Pei, V. Sorkin, and Y.-W. Zhang, “A modified Tersoff potential for pure and hydrogenated diamond-like carbon,” Computational Materials Science. 2013. link Times cited: 56 NOT USED (low confidence) S. Furmaniak, A. Terzyk, K. Kaneko, P. A. Gauden, P. Kowlaczyk, and T. Itoh, “The first atomistic modelling-aided reproduction of morphologically defective single walled carbon nanohorns.,” Physical chemistry chemical physics : PCCP. 2013. link Times cited: 10 Abstract: A new modelling-aided approach for the atomistic model of si… read moreAbstract: A new modelling-aided approach for the atomistic model of single walled carbon nanohorn (SWNH) creation is presented, based on experimental evidence, on realistic potential of carbon-carbon interactions and on molecular simulations. A new model of SWNHs is next used to predict Ar adsorption properties and to check the molecular fundamentals of the adsorption mechanism. The influence of the apex angle value, nanohorn diameter and nanohorn length on the shapes of isotherms, enthalpy, high resolution α(s)-plots and adsorption potential distribution curves is checked. Finally the comparison with new experimental Ar adsorption results is shown and the conclusions on the porosity of real SWNH aggregates are given. read less NOT USED (low confidence) I. Suarez-Martinez and N. Marks, “Amorphous carbon nanorods as a precursor for carbon nanotubes,” Carbon. 2012. link Times cited: 18 NOT USED (low confidence) J. Palmer and K. Gubbins, “Atomistic models for disordered nanoporous carbons using reactive force fields,” Microporous and Mesoporous Materials. 2012. link Times cited: 75 NOT USED (low confidence) B. A. Fairchild et al., “Mechanism for the Amorphisation of Diamond,” Advanced Materials. 2012. link Times cited: 72 Abstract: The breakdown of the diamond lattice is explored by ion impl… read moreAbstract: The breakdown of the diamond lattice is explored by ion implantation and molecular dynamics simulations. We show that lattice breakdown is strain-driven, rather than damage-driven, and that the lattice persists until 16% of the atoms have been removed from their lattice sites. The figure shows the transition between amorphous carbon and diamond, with the interfaces highlighted with dashed lines. read less NOT USED (low confidence) D. Spagnoli and J. Gale, “Atomistic theory and simulation of the morphology and structure of ionic nanoparticles.,” Nanoscale. 2012. link Times cited: 12 Abstract: Computational techniques are widely used to explore the stru… read moreAbstract: Computational techniques are widely used to explore the structure and properties of nanomaterials. This review surveys the application of both quantum mechanical and force field based atomistic simulation methods to nanoparticles, with a particular focus on the methodologies available and the ways in which they can be utilised to study structure, phase stability and morphology. The main focus of this article is on partially ionic materials, from binary semiconductors through to mineral nanoparticles, with more detailed considered of three examples, namely titania, zinc sulphide and calcium carbonate. read less NOT USED (low confidence) N. Marks, M. Lattemann, and D. Mckenzie, “Nonequilibrium route to nanodiamond with astrophysical implications.,” Physical review letters. 2012. link Times cited: 21 Abstract: Nanometer-sized diamond grains are commonly found in primiti… read moreAbstract: Nanometer-sized diamond grains are commonly found in primitive chondritic meteorites, but their origin is puzzling. Using evidence from atomistic simulation, we establish a mechanism by which nanodiamonds form abundantly in space in a two-stage process involving condensation of vapor to form carbon onions followed by transformation to nanodiamond in an energetic impact. This nonequilibrium process is consistent with common environments in space and invokes the fewest assumptions of any proposed model. Accordingly, our model can explain nanodiamond formation in both presolar and solar environments. The model provides an attractive framework for understanding noble gas incorporation and explains all key features of meteoritic nanodiamond, including size, shape, and polytype. By understanding the creation of nanodiamonds, new opportunities arise for their exploitation as a powerful astrophysical probe. read less NOT USED (low confidence) S. Furmaniak, A. Terzyk, P. A. Gauden, N. Marks, R. Powles, and P. Kowalczyk, “Simulating the changes in carbon structure during the burn-off process.,” Journal of colloid and interface science. 2011. link Times cited: 16 NOT USED (low confidence) J. Palmer, J. D. Moore, J. Brennan, and K. Gubbins, “Adsorption and diffusion of argon in disordered nanoporous carbons,” Adsorption. 2011. link Times cited: 23 NOT USED (low confidence) F. Song et al., “Calibrating the atomic balance by carbon nanoclusters,” arXiv: Mesoscale and Nanoscale Physics. 2010. link Times cited: 8 Abstract: Carbon atoms are counted at near atomic-level precision usin… read moreAbstract: Carbon atoms are counted at near atomic-level precision using a scanning transmission electron microscope calibrated by carbon nanocluster mass standards. A linear calibration curve governs the working zone from a few carbon atoms up to 34,000 atoms. This linearity enables adequate averaging of the scattering cross sections, imparting the experiment with near atomic-level precision despite the use of a coarse mass reference. An example of this approach is provided for thin layers of stacked graphene sheets. Suspended sheets with a thickness below 100 nm are visualized, providing quantitative measurement in a regime inaccessible to optical and scanning probe methods. read less NOT USED (low confidence) J. Palmer et al., “Modeling the structural evolution of carbide-derived carbons using quenched molecular dynamics,” Carbon. 2010. link Times cited: 170 NOT USED (low confidence) D. Duffy, “Modeling plasma facing materials for fusion power,” Materials Today. 2009. link Times cited: 25 NOT USED (low confidence) M. B. Taylor et al., “The origin of preferred orientation during carbon film growth,” Journal of Physics: Condensed Matter. 2009. link Times cited: 16 Abstract: Carbon films were prepared using a filtered cathodic vacuum … read moreAbstract: Carbon films were prepared using a filtered cathodic vacuum arc deposition system operated with a substrate bias varying linearly with time during growth. Ion energies were in the range between 95 and 620 eV. Alternating dark, high density (sp3 rich) bands and light, low density (sp2 rich) bands were observed using cross-sectional transmission electron microscopy, corresponding to abrupt transitions between materials with densities of approximately 3.1 and 2.6 g cm−3. No intermediate densities were observed in the samples. The low density bands show strong preferred orientation with graphitic sheets aligned normal to the film. After annealing, the low density bands became more oriented and the thinner high density layers were converted to low density material. In molecular dynamics modelling of film growth, temperature activated structural rearrangements occurring over long timescales ( ps) caused the transition from sp3 rich to oriented sp2 rich structure. Once this oriented growth was initiated, the sputtering yield decreased and channelling was observed. However, we conclude that sputtering and channelling events, while they occur, are not the cause of the transition to the oriented structure. read less NOT USED (low confidence) M. Zhao, M. Iron, P. Staszewski, N. E. Schultz, R. Valero, and D. Truhlar, “Valence-Bond Order (VBO): A New Approach to Modeling Reactive Potential Energy Surfaces for Complex Systems, Materials, and Nanoparticles.,” Journal of chemical theory and computation. 2009. link Times cited: 12 Abstract: The extension of molecular mechanics to reactive systems, me… read moreAbstract: The extension of molecular mechanics to reactive systems, metals, and covalently bonded clusters with variable coordination numbers requires new functional forms beyond those popular for organic chemistry and biomolecules. Here we present a new scheme for reactive molecular mechanics, which is denoted as the valence-bond order model, for approximating reactive potential energy surfaces in large molecules, clusters, nanoparticles, solids, and other condensed-phase materials, especially those containing metals. The model is motivated by a moment approximation to tight binding molecular orbital theory, and we test how well one can approximate potential energy surfaces with a very simple functional form involving only interatomic distances with no explicit dependence on bond angles or dihedral angles. For large systems the computational requirements scale linearly with system size, and no diagonalizations or iterations are required; thus the method is well suited to large-scale simulations. The method is illustrated here by developing a force field for particles and solids composed of aluminum and hydrogen. The parameters were optimized against both interaction energies and relative interaction energies. The method performs well for pure aluminum clusters, nanoparticles, and bulk lattices and reasonably well for pure hydrogen clusters; the mean unsigned error per atom for the aluminum-hydrogen clusters is 0.1 eV/atom. read less NOT USED (low confidence) G. Opletal, T. Petersen, B. O’Malley, I. Snook, D. McCulloch, and I. Yarovsky, “HRMC: Hybrid Reverse Monte Carlo method with silicon and carbon potentials,” Comput. Phys. Commun. 2008. link Times cited: 21 NOT USED (low confidence) D. Lau et al., “Abrupt stress induced transformation in amorphous carbon films with a highly conductive transition phase.,” Physical review letters. 2008. link Times cited: 94 Abstract: We demonstrate that when, and only when, the biaxial stress … read moreAbstract: We demonstrate that when, and only when, the biaxial stress is increased above a critical value of 6+/-1 GPa during the growth of a carbon film at room temperature, tetrahedral amorphous carbon is formed. This confirms that the stress present during the formation of an amorphous carbon film determines its sp;{3} bonding fraction. In the vicinity of the critical stress, a highly oriented graphitelike material is formed which exhibits low electrical resistance and provides Ohmic contacts to silicon. Atomistic simulations reveal that the structural transitions are thermodynamically driven and not the result of dynamical effects. read less NOT USED (low confidence) M. Mrovec, M. Moseler, C. Elsasser, and P. Gumbsch, “Atomistic modeling of hydrocarbon systems using analytic bond-order potentials,” Progress in Materials Science. 2007. link Times cited: 27 NOT USED (low confidence) N. Marks, M. F. Cover, and C. Kocer, “Simulating temperature effects in the growth of tetrahedral amorphous carbon: The importance of infrequent events,” Applied Physics Letters. 2006. link Times cited: 32 Abstract: This thin-film deposition study of tetrahedral amorphous car… read moreAbstract: This thin-film deposition study of tetrahedral amorphous carbon shows that including infrequent processes on the millisecond scale substantially improves the accuracy of molecular dynamics simulations. Elevated temperature between energetic impacts is used to activate processes which are typically ignored. In agreement with experiment, the simulations show an abrupt transition in which diamondlike carbon transforms into vertically oriented graphitic sheets. The simulations also highlight the importance of infrequent events in combination with energetic impact. In the absence of the latter, the transition temperature is significantly higher, in good correlation with experiment. read less NOT USED (low confidence) J. Los, L. Ghiringhelli, E. Meijer, and A. Fasolino, “Improved long-range reactive bond-order potential for carbon. I. Construction (Correction on vol 72, pg 214102, 2005),” Acta Crystallographica Section B-structural Science. 2005. link Times cited: 181 Abstract: We present LCBOPII, an improvement of the long-range carbon … read moreAbstract: We present LCBOPII, an improvement of the long-range carbon bond-order potential (LCBOP) by Los and Fasolino [Phys. Rev. B 68, 024107 (2003)]. LCBOPII contains a coordination dependent medium range term for bond distances between 1.7 and $4\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$, meant to reproduce the dissociation energy curves for single, double, and triple bonds and improve the reactive properties as well as the description of the liquid and of low coordinated phases. Other features of LCBOPII are a coordination dependent angular correlation, a correction for antibonding states, and a conjugation dependent torsional interaction based on ab initio calculations of the torsional barriers for a set of molecular configurations. We present results for the geometry and energetics of the graphite-to-diamond transformation and of the vacancy in diamond and graphite as well as the prediction of the energy barrier of the 5-77-5 defect in graphite and graphene for which ab initio results are available only for unsuitably small samples. In the accompanying paper (Ghiringhelli et al., Phys. Rev. B 72, 214103 (2005) we use LCBOPII to evaluate several properties, including the equation of state, of liquid carbon. read less NOT USED (low confidence) T. Petersen, I. Snook, I. Yarovsky, and D. McCulloch, “Monte Carlo based modeling of carbon nanostructured surfaces,” Physical Review B. 2005. link Times cited: 11 Abstract: We have developed Monte Carlo based algorithms to produce re… read moreAbstract: We have developed Monte Carlo based algorithms to produce realistic models of complex carbon nanostructures with nontrivial curvature, including fullerene junctions between nanotubes. The models are constructed by first analytically defining curved surfaces and then optimizing the configuration of carbon atoms on these surfaces using a realistic interatomic potential. We illustrate our method by generating several previously proposed and also new types of structures, which all show realistic physical properties. Our method is not limited to these structures and can be used to generate large models of nanostructured materials with complex surface geometries and porous structure on the nano-scale. read less NOT USED (low confidence) Q. Lu and B. Bhattacharya, “The role of atomistic simulations in probing the small-scale aspects of fracture—a case study on a single-walled carbon nanotube,” Engineering Fracture Mechanics. 2005. link Times cited: 71 NOT USED (low confidence) W（张伟） Zhang, Z. Xu, and Z. Zhu, “STUDY OF THERMAL STABILITY OF FULLERENES BY MOLECULAR DYNAMICS,” International Journal of Modern Physics B. 2005. link Times cited: 4 Abstract: The thermal stability of fullerene C20, C26, C36 and C60 is … read moreAbstract: The thermal stability of fullerene C20, C26, C36 and C60 is studied using Molecular Dynamics (MD) simulation based on Brenner potential in this work. Lindemann's relative root-mean-square (rms) bond-length fluctuation is used to monitor the behavior of the structural and thermal properties. The results show that the rms bond-length fluctuation becomes scattered points at relative high tempereture, which is caused by different isomerization transitions. Larger fullerenes are found to be more stable than small ones. The results are compared with those from MD simulation based on TLHT potential. Mechanic stability of fullerene C20 is also studied. read less NOT USED (low confidence) P. Zetterström, S. Trabesinger, F. Lindberg, R. Delaplane, J. Leis, and G. Svensson, “Reverse Monte Carlo studies of nanoporous carbon from TiC,” Journal of Physics: Condensed Matter. 2005. link Times cited: 48 Abstract: The structures of nanoporous carbon prepared by chlorination… read moreAbstract: The structures of nanoporous carbon prepared by chlorination of TiC at five different temperatures (700–1100 °C) have been studied by means of reverse Monte Carlo modelling of neutron diffraction data S(q), 0.3 read less NOT USED (low confidence) G. Staszewska, P. Staszewski, N. E. Schultz, and D. Truhlar, “Many-body tight-binding model for aluminum nanoparticles,” Physical Review B. 2005. link Times cited: 8 Abstract: A new, parametrized many-body tight-binding model is propose… read moreAbstract: A new, parametrized many-body tight-binding model is proposed for calculating the potential energy surface for aluminum nanoparticles. The parameters have been fitted to reproduce the energies for a variety of aluminum clusters (Al{sub 2}, Al{sub 3}, Al{sub 4}, Al{sub 7}, Al{sub 13}) calculated recently by the PBE0/MG3 method as well as the experimental face-centered-cubic cohesive energy, lattice constant, and a small set of Al cluster ionization potentials. Several types of parametrization are presented and compared. The mean unsigned error per atom for the best model is less than 0.03 eV. read less NOT USED (low confidence) A. Harada, F. Shimojo, and K. Hoshino, “Molecular-dynamics Studies on Hydrogen Atoms in Nanostructured Graphite,” Molecular Simulation. 2004. link Times cited: 5 Abstract: We have investigated the effect of crystallization on the de… read moreAbstract: We have investigated the effect of crystallization on the desorption of hydrogen atoms from nanostructured graphite by carrying out the hybrid molecular-dynamics simulation on model systems. It is shown by our simulation that the bond between hydrogen and carbon atoms becomes weaker due to the recrystallization of the nanostructured graphite and that the hydrogen dimer is formed with increasing temperature. We have thus found one possible mechanism of the hydrogen desorption from the nanostructured graphite. read less NOT USED (low confidence) Z. Yao, J.-S. Wang, B. Li, and G.-rong Liu, “Thermal conduction of carbon nanotubes using molecular dynamics,” Physical Review B. 2004. link Times cited: 131 Abstract: The heat flux autocorrelation functions of carbon nanotubes … read moreAbstract: The heat flux autocorrelation functions of carbon nanotubes (CNTs) with different radius and lengths is calculated using equilibrium molecular dynamics. The thermal conductance of CNTs is also calculated using the Green-Kubo relation from the linear response theory. By pointing out the ambiguity in the cross section definition of single wall CNTs, we use the thermal conductance instead of conductivity in calculations and discussions. We find that the thermal conductance of CNTs diverges with the CNT length. After the analysis of vibrational density of states, it can be concluded that more low frequency vibration modes exist in longer CNTs, and they effectively contribute to the divergence of thermal conductance. read less NOT USED (low confidence) D. Mckenzie et al., “Voltage dependence of cluster size in carbon films using plasma immersion ion implantation,” Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms. 2003. link Times cited: 9 NOT USED (low confidence) A. Harada, F. Shimojo, and K. Hoshino, “Dynamic Properties of Disordered Phases of Carbon Studied by an Empirical Potential: Stringent Tests toward Hybrid Approach with the Density-Functional Theory,” Journal of the Physical Society of Japan. 2003. link Times cited: 9 Abstract: The dynamic properties of the liquid and the amorphous carbo… read moreAbstract: The dynamic properties of the liquid and the amorphous carbon are studied by empirical-potential molecular-dynamics (MD) simulations as well as ab initio MD methods based on the density-functional theory. As the empirical potential, the environment-dependent interatomic potential (EDIP) proposed recently by Marks is used. Detailed investigations on the density–density time correlation function, known as van Hove correlation functions, are given. It is shown that the EDIP is extremely transferable in the sense that the dynamic properties, as well as the static properties, of the disordered phases of carbon are well reproduced using the EDIP. It is also shown that the EDIP is usable for the hybrid ab initio /empirical-potential MD simulation, by applying the hybrid method to a graphite sheet (graphen) for investigating the dynamic properties such as the heat transfer. read less NOT USED (low confidence) G. Opletal et al., “Hybrid approach for generating realistic amorphous carbon structure using metropolis and reverse Monte Carlo,” Molecular Simulation. 2002. link Times cited: 112 Abstract: An improved method for the modelling of carbon structures ba… read moreAbstract: An improved method for the modelling of carbon structures based on a hybrid reverse Monte Carlo (HRMC) method is presented. This algorithm incorporates an accurate environment dependent interaction potential (EDIP) in conjunction with the commonly used constraints derived from experimental data. In this work, we compare this new method with other modelling results for a small system of 2.9 g/cc amorphous carbon. We find that the new approach greatly improves the structural description, alleviating the common problem in standard reverse Monte Carlo method (RMC) of generating structures with a high proportion of unphysical small rings. The advantage of our method is that larger systems can now be modelled, allowing the incorporation of mesoscopic scale features. read less NOT USED (low confidence) A. Barnard and S. Russo, “Development of an improved Stillinger-Weber potential for tetrahedral carbon using ab initio (Hartree-Fock and MP2) methods,” Molecular Physics. 2002. link Times cited: 28 Abstract: An improved interatomic potential for tetrahedral carbon is … read moreAbstract: An improved interatomic potential for tetrahedral carbon is presented. This potential is of the Stillinger-Weber (SW) type and has been determined from calculations performed on a select group of small hydrocarbon molecules, chosen for their similarities to the tetrahedral lattice of bulk diamond. Counterpoise corrected Hartree-Fock (HF) and second-order Møller-Plesset perturbation theory (MP2) calculations were performed on ethane, 2,2-dimethylpropane (neo-pentane, (C5H12), 2-dimethyl-3-dimethylbutane (neobutane, C8H18) and cyclohexane (C6H12) in order to determine the two-body (stretching) and three-body (bond bending) energies. The suitability of these molecules to model the properties of diamond was determined by comparison of CC bond length, well depth, CCC bond angle, simultaneous stretch and bend energy and force constants to those of bulk diamond. It was found that neopentane provided the best overall description of tetrahedral bonded carbon. The ab initio derived stretch and bend energies were fitted to the SW potential energy terms and the SW parameters calculated. The newly parametrized SW potential was then evaluated by calculating the stretch force constants, elastic constants and the X-point phonon modes of bulk diamond. read less NOT USED (low confidence) A. Moafi, O. Heidari, B. Soltannia, D. McCulloch, and P. Parvin, “Changes in oriented graphitic carbon properties upon exposure to atomic hydrogen,” Diamond and Related Materials. 2020. link Times cited: 1 NOT USED (low confidence) A. Sircar and P. Patra, “Rolling and Sliding Resistance as Carbon Nanotubes are Driven on a Graphene Sheet.” 2020. link Times cited: 0 NOT USED (low confidence) C. Shang and Z. Liu, “Stochastic Surface Walking Method and Applications to Real Materials,” Handbook of Materials Modeling. 2019. link Times cited: 0 NOT USED (low confidence) S. Winczewski, M. Y. Shaheen, and J. Rybicki, “Interatomic potential suitable for the modeling of penta-graphene: Molecular statics/molecular dynamics studies,” Carbon. 2018. link Times cited: 34 NOT USED (low confidence) B. Schultrich, “Structure of Amorphous Carbon.” 2018. link Times cited: 2 NOT USED (low confidence) B. Schultrich, “Growth of ta-C Films.” 2018. link Times cited: 0 NOT USED (low confidence) P. Kowalczyk et al., “Morphologically disordered pore model for characterization of micro-mesoporous carbons,” Carbon. 2017. link Times cited: 23 NOT USED (low confidence) J. Houška, “Force field for realistic molecular dynamics simulations of ZrO2 growth,” Computational Materials Science. 2016. link Times cited: 12 NOT USED (low confidence) Y. Zhao, L. Peng, and G. Yu, “Electrochemical Hierarchical Composites.” 2015. link Times cited: 2 NOT USED (low confidence) N. Marks, “Amorphous Carbon and Related Materials.” 2010. link Times cited: 7 NOT USED (low confidence) L. Ghiringhelli and E. Meijer, “Liquid carbon: Freezing line and structure near freezing.” 2010. link Times cited: 5 NOT USED (low confidence) M. Biggs, “Molecular simulations for nanofluids.” 2010. link Times cited: 0 NOT USED (low confidence) H. Bock, K. Gubbins, and J. Pikunic, “Models of Porous Carbons.” 2008. link Times cited: 6 NOT USED (low confidence) R. Khare, S. L. Mielke, J. T. Paci, S. Zhang, G. Schatz, and T. Belytschko, “Two quantum mechanical/molecular mechanical coupling schemes appropriate for fracture mechanics studies.” 2007. link Times cited: 10 Abstract: Many coupled quantum mechanical/molecular mechanical (QM/MM)… read moreAbstract: Many coupled quantum mechanical/molecular mechanical (QM/MM) methods employ disjoint sub domains for the MM and QM regions together with link atoms to ameliorate the effects of severing covalent bonds that straddle the QM/MM interface. In the context of simulations of mechanical properties, this can be problematic because the interactions bet ween the subdomains are then modeled by bonds involving link atoms and such bonds typically do not closely resemble those of the original system. In this paper we consider two coupling schemes that employ overlapping domains. The first is the ONIOM schem e of Morokuma et al. that includes an MM treatment of the entire system together with QM corrections for key subdomains. The second is a new approach that we will refer to as the overlapping domain link atom (ODLA) method. This method involves only a min imal overlap between the QM and MM subdomains. One important advantage of the ODLA scheme as compared to the ONIOM method is that, within the region that is treated entirely by QM methods, chemical interactions can be modeled for which reliable MM potenti als are unavailable. Results of fracture studies of defected graphene sheets obtained with the ONIOM and ODLA methods are compared to benchmark results obtained by an entirely QM treatment. Both coupling methods perform well and the two coupling methods display very close agreement. read less NOT USED (low confidence) T. Petersen, I. Yarovsky, I. Snook, D. McCulloch, and G. Opletal, “Structural analysis of carbonaceous solids using an adapted reverse Monte Carlo algorithm,” Carbon. 2003. link Times cited: 50 NOT USED (high confidence) F. Polewczyk, J.-M. Leyssale, and P. Lafourcade, “Temperature-dependent elasticity of single crystalline graphite,” Computational Materials Science. 2023. link Times cited: 1 NOT USED (high confidence) M. Qamar, M. Mrovec, Y. Lysogorskiy, A. Bochkarev, and R. Drautz, “Atomic Cluster Expansion for Quantum-Accurate Large-Scale Simulations of Carbon.,” Journal of chemical theory and computation. 2022. link Times cited: 17 Abstract: We present an atomic cluster expansion (ACE) for carbon that… read moreAbstract: We present an atomic cluster expansion (ACE) for carbon that improves over available classical and machine learning potentials. The ACE is parametrized from an exhaustive set of important carbon structures over extended volume and energy ranges, computed using density functional theory (DFT). Rigorous validation reveals that ACE accurately predicts a broad range of properties of both crystalline and amorphous carbon phases while being several orders of magnitude more computationally efficient than available machine learning models. We demonstrate the predictive power of ACE on three distinct applications: brittle crack propagation in diamond, the evolution of amorphous carbon structures at different densities and quench rates, and the nucleation and growth of fullerene clusters under high-pressure and high-temperature conditions. read less NOT USED (high confidence) Z. El-Machachi, M. Wilson, and V. L. Deringer, “Exploring the configurational space of amorphous graphene with machine-learned atomic energies,” Chemical Science. 2022. link Times cited: 4 Abstract: Two-dimensionally extended amorphous carbon (“amorphous grap… read moreAbstract: Two-dimensionally extended amorphous carbon (“amorphous graphene”) is a prototype system for disorder in 2D, showing a rich and complex configurational space that is yet to be fully understood. Here we explore the nature of amorphous graphene with an atomistic machine-learning (ML) model. We create structural models by introducing defects into ordered graphene through Monte-Carlo bond switching, defining acceptance criteria using the machine-learned local, atomic energies associated with a defect, as well as the nearest-neighbor (NN) environments. We find that physically meaningful structural models arise from ML atomic energies in this way, ranging from continuous random networks to paracrystalline structures. Our results show that ML atomic energies can be used to guide Monte-Carlo structural searches in principle, and that their predictions of local stability can be linked to short- and medium-range order in amorphous graphene. We expect that the former point will be relevant more generally to the study of amorphous materials, and that the latter has wider implications for the interpretation of ML potential models. read less NOT USED (high confidence) G. Jeanmairet, B. Rotenberg, and M. Salanne, “Microscopic Simulations of Electrochemical Double-Layer Capacitors,” Chemical Reviews. 2022. link Times cited: 54 Abstract: Electrochemical double-layer capacitors (EDLCs) are devices … read moreAbstract: Electrochemical double-layer capacitors (EDLCs) are devices allowing the storage or production of electricity. They function through the adsorption of ions from an electrolyte on high-surface-area electrodes and are characterized by short charging/discharging times and long cycle-life compared to batteries. Microscopic simulations are now widely used to characterize the structural, dynamical, and adsorption properties of these devices, complementing electrochemical experiments and in situ spectroscopic analyses. In this review, we discuss the main families of simulation methods that have been developed and their application to the main family of EDLCs, which include nanoporous carbon electrodes. We focus on the adsorption of organic ions for electricity storage applications as well as aqueous systems in the context of blue energy harvesting and desalination. We finally provide perspectives for further improvement of the predictive power of simulations, in particular for future devices with complex electrode compositions. read less NOT USED (high confidence) C.-gen Qian, B. Mclean, D. Hedman, and F. Ding, “A comprehensive assessment of empirical potentials for carbon materials,” APL Materials. 2021. link Times cited: 22 Abstract: Carbon materials and their unique properties have been exten… read moreAbstract: Carbon materials and their unique properties have been extensively studied by molecular dynamics, thanks to the wide range of available carbon bond order potentials (CBOPs). Recently, with the increase in popularity of machine learning (ML), potentials such as Gaussian approximation potential (GAP), trained using ML, can accurately predict results for carbon. However, selecting the right potential is crucial as each performs differently for different carbon allotropes, and these differences can lead to inaccurate results. This work compares the widely used CBOPs and the GAP-20 ML potential with density functional theory results, including lattice constants, cohesive energies, defect formation energies, van der Waals interactions, thermal stabilities, and mechanical properties for different carbon allotropes. We find that GAP-20 can more accurately predict the structure, defect properties, and formation energies for a variety of crystalline phase carbon compared to CBOPs. Importantly, GAP-20 can simulate the thermal stability of C60 and the fracture of carbon nanotubes and graphene accurately, where CBOPs struggle. However, similar to CBOPs, GAP-20 is unable to accurately account for van der Waals interactions. Despite this, we find that GAP-20 outperforms all CBOPs assessed here and is at present the most suitable potential for studying thermal and mechanical properties for pristine and defective carbon. read less NOT USED (high confidence) B. Parsaeifard, D. De, J. A. Finkler, and S. Goedecker, “Fingerprint-Based Detection of Non-Local Effects in the Electronic Structure of a Simple Single Component Covalent System,” Condensed Matter. 2021. link Times cited: 5 Abstract: Using fingerprints used mainly in machine learning schemes o… read moreAbstract: Using fingerprints used mainly in machine learning schemes of the potential energy surface, we detect in a fully algorithmic way long range effects on local physical properties in a simple covalent system of carbon atoms. The fact that these long range effects exist for many configurations implies that atomistic simulation methods, such as force fields or modern machine learning schemes, that are based on locality assumptions, are limited in accuracy. We show that the basic driving mechanism for the long range effects is charge transfer. If the charge transfer is known, locality can be recovered for certain quantities such as the band structure energy. read less NOT USED (high confidence) Y.-C. Wang, Y. Zhu, and H. Wu, “Porous Characteristics of Three-Dimensional Disordered Graphene Networks,” Crystals. 2021. link Times cited: 8 Abstract: The porous characteristics of disordered carbons are critica… read moreAbstract: The porous characteristics of disordered carbons are critical factors to their performance on hydrogen storage and electrochemical capacitors. Even though the porous information can be estimated indirectly by gas adsorption experiments, it is still hard to directly characterize the porous morphology considering the complex 3D connectivity. To this end, we construct full-atom disordered graphene networks (DGNs) by mimicking the chlorination process of carbide-derived carbons using annealing-MD simulations, which could model the structure of disordered carbons at the atomic scale. The porous characteristics, including pore volume, pore size distribution (PSD), and specific surface area (SSA), were then computed from the coordinates of carbon atoms. From the evolution of structural features, pores grow dramatically during the formation of polyaromatic fragments and sequent disordered framework. Then structure is further graphitized while the PSD shows little change. For the obtained DGNs, the porosity, pore size, and SSA increase with decreasing density. Furthermore, SSA tends to saturate in the low-density range. The DGNs annealed at low temperatures exhibit larger SSA than high-temperature DGNs because of the abundant free edges. read less NOT USED (high confidence) J. Ehrens et al., “Theoretical formation of carbon nanomembranes under realistic conditions using classical molecular dynamics,” Physical Review B. 2020. link Times cited: 2 Abstract: Carbon nanomembranes made from aromatic precursor molecules … read moreAbstract: Carbon nanomembranes made from aromatic precursor molecules are free standing nanometer thin materials of macroscopic lateral dimensions. Although produced in various versions for about two decades not much is known about their internal structure. Here we present a first systematic theoretical attempt to model the formation, structure, and mechanical properties of carbon nanomembranes using classical molecular dynamics simulations. read less NOT USED (high confidence) P. Rowe, V. L. Deringer, P. Gasparotto, G. Csányi, and A. Michaelides, “An accurate and transferable machine learning potential for carbon.,” The Journal of chemical physics. 2020. link Times cited: 120 Abstract: We present an accurate machine learning (ML) model for atomi… read moreAbstract: We present an accurate machine learning (ML) model for atomistic simulations of carbon, constructed using the Gaussian approximation potential (GAP) methodology. The potential, named GAP-20, describes the properties of the bulk crystalline and amorphous phases, crystal surfaces, and defect structures with an accuracy approaching that of direct ab initio simulation, but at a significantly reduced cost. We combine structural databases for amorphous carbon and graphene, which we extend substantially by adding suitable configurations, for example, for defects in graphene and other nanostructures. The final potential is fitted to reference data computed using the optB88-vdW density functional theory (DFT) functional. Dispersion interactions, which are crucial to describe multilayer carbonaceous materials, are therefore implicitly included. We additionally account for long-range dispersion interactions using a semianalytical two-body term and show that an improved model can be obtained through an optimization of the many-body smooth overlap of atomic positions descriptor. We rigorously test the potential on lattice parameters, bond lengths, formation energies, and phonon dispersions of numerous carbon allotropes. We compare the formation energies of an extensive set of defect structures, surfaces, and surface reconstructions to DFT reference calculations. The present work demonstrates the ability to combine, in the same ML model, the previously attained flexibility required for amorphous carbon [V. L. Deringer and G. Csányi, Phys. Rev. B 95, 094203 (2017)] with the high numerical accuracy necessary for crystalline graphene [Rowe et al., Phys. Rev. B 97, 054303 (2018)], thereby providing an interatomic potential that will be applicable to a wide range of applications concerning diverse forms of bulk and nanostructured carbon. read less NOT USED (high confidence) M. A. Caro, G. Csányi, T. Laurila, and V. L. Deringer, “Machine learning driven simulated deposition of carbon films: From low-density to diamondlike amorphous carbon,” Physical Review B. 2020. link Times cited: 29 Abstract: © 2020 American Physical Society. Amorphous carbon (a-C) mat… read moreAbstract: © 2020 American Physical Society. Amorphous carbon (a-C) materials have diverse interesting and useful properties, but the understanding of their atomic-scale structures is still incomplete. Here, we report on extensive atomistic simulations of the deposition and growth of a-C films, describing interatomic interactions using a machine learning (ML) based Gaussian approximation potential model. We expand widely on our initial work [M. A. Caro, Phys. Rev. Lett. 120, 166101 (2018)PRLTAO0031-900710.1103/PhysRevLett.120.166101] by now considering a broad range of incident ion energies, thus modeling samples that span the entire range from low-density (sp2-rich) to high-density (sp3-rich, "diamondlike") amorphous forms of carbon. Two different mechanisms are observed in these simulations, depending on the impact energy: low-energy impacts induce sp- and sp2-dominated growth directly around the impact site, whereas high-energy impacts induce peening. Furthermore, we propose and apply a scheme for computing the anisotropic elastic properties of the a-C films. Our work provides fundamental insight into this intriguing class of disordered solids, as well as a conceptual and methodological blueprint for simulating the atomic-scale deposition of other materials with ML driven molecular dynamics. read less NOT USED (high confidence) X. Huang et al., “The mechanical response of glassy carbon recovered from high pressure,” Journal of Applied Physics. 2020. link Times cited: 6 Abstract: Glassy carbon (GC) is usually considered the prototypical su… read moreAbstract: Glassy carbon (GC) is usually considered the prototypical super-elastic material, which can almost fully recover its shape after compression of several gigapascals (GPa). In this work, nanoindentation is used to study the mechanical response of GC, which was subjected to a range of high pressures using a diamond anvil cell (DAC). We show that GC starts to lose its elasticity after compression to 6 GPa and becomes clearly mechanically anisotropic after being compressed beyond ∼30 GPa. Molecular dynamics (MD) simulations are used to calculate Young's modulus before and after compression. Through our experimental results and MD simulations, we show that the elasticity of GC is at a minimum around 30 GPa but recovers after compression to higher pressures along the DAC compression axis. read less NOT USED (high confidence) M. Ishida and T. Ohba, “Hybrid Reverse Molecular Dynamics Simulation as New Approach to Determination of Carbon Nanostructure of Carbon Blacks,” Scientific Reports. 2020. link Times cited: 7 NOT USED (high confidence) L. Safina, J. Baimova, and R. Mulyukov, “Nickel nanoparticles inside carbon nanostructures: atomistic simulation,” Mechanics of Advanced Materials and Modern Processes. 2019. link Times cited: 17 NOT USED (high confidence) J. Huang, G. Csányi, J. Zhao, J. Cheng, and V. L. Deringer, “First-principles study of alkali-metal intercalation in disordered carbon anode materials,” Journal of Materials Chemistry A. 2019. link Times cited: 36 Abstract: The intercalation of alkali metals in disordered carbon anod… read moreAbstract: The intercalation of alkali metals in disordered carbon anode materials is studied by a combination of first-principles and machine-learning methods. read less NOT USED (high confidence) R. Jana, D. Savio, V. L. Deringer, and L. Pastewka, “Structural and elastic properties of amorphous carbon from simulated quenching at low rates,” Modelling and Simulation in Materials Science and Engineering. 2019. link Times cited: 22 Abstract: We generate representative structural models of amorphous ca… read moreAbstract: We generate representative structural models of amorphous carbon (a-C) from constant-volume quenching from the liquid with subsequent relaxation of internal stresses in molecular dynamics simulations using empirical and machine-learning interatomic potentials. By varying volume and quench rate we generate structures with a range of density and amorphous morphologies. We find that all a-C samples show a universal relationship between hybridization, bulk modulus and density despite having distinctly different cohesive energies. Differences in cohesive energy are traced back to slight changes in the distribution of bond-angles that is likely linked to thermal stability of these structures. read less NOT USED (high confidence) A. Savin and M. Mazo, “The COMPASS force field: Validation for carbon nanoribbons,” Physica E: Low-dimensional Systems and Nanostructures. 2018. link Times cited: 23 NOT USED (high confidence) B. D. Jensen, G. Odegard, J.-W. Kim, G. Sauti, E. Siochi, and K. Wise, “Simulating the effects of carbon nanotube continuity and interfacial bonding on composite strength and stiffness.,” Composites science and technology. 2018. link Times cited: 25 NOT USED (high confidence) M. A. Caro, V. L. Deringer, J. Koskinen, T. Laurila, and G. Csányi, “Growth Mechanism and Origin of High sp^3 Content in Tetrahedral Amorphous Carbon.,” Physical review letters. 2018. link Times cited: 99 Abstract: We study the deposition of tetrahedral amorphous carbon (ta-… read moreAbstract: We study the deposition of tetrahedral amorphous carbon (ta-C) films from molecular dynamics simulations based on a machine-learned interatomic potential trained from density-functional theory data. For the first time, the high sp^{3} fractions in excess of 85% observed experimentally are reproduced by means of computational simulation, and the deposition energy dependence of the film's characteristics is also accurately described. High confidence in the potential and direct access to the atomic interactions allow us to infer the microscopic growth mechanism in this material. While the widespread view is that ta-C grows by "subplantation," we show that the so-called "peening" model is actually the dominant mechanism responsible for the high sp^{3} content. We show that pressure waves lead to bond rearrangement away from the impact site of the incident ion, and high sp^{3} fractions arise from a delicate balance of transitions between three- and fourfold coordinated carbon atoms. These results open the door for a microscopic understanding of carbon nanostructure formation with an unprecedented level of predictive power. read less NOT USED (high confidence) A. Shiryaev et al., “Ion implantation in nanodiamonds: size effect and energy dependence,” Scientific Reports. 2018. link Times cited: 25 NOT USED (high confidence) M. Chávez-Castillo, M. Rodríguez-Meza, and L. Meza-Montes, “Mechanical response of bilayer silicene nanoribbons under uniaxial tension,” RSC Advances. 2018. link Times cited: 3 Abstract: Understanding the behaviour of nanoscale systems is of great… read moreAbstract: Understanding the behaviour of nanoscale systems is of great importance to tailor their properties. To this aim, we investigate the Young's modulus (YM) of defect-free and defective armchair bilayer silicene nanoribbons (SNRs), at room temperature, as a function of length and distance between layers. In this study, we perform molecular dynamics simulations using the environment-dependent interatomic potential to describe the interaction of the Si atoms. We show that the Young's modulus of pristine and defective bilayer SNRs increases with the ribbon length exhibiting size dependence. In general, YM of defective bilayer SNRs is smaller than the value obtained for the defect-free case, as a result of the number of missing bonds. In all cases, as the interlayer distance increases YM decreases and the buckling increases. It is shown that the YM exhibits a quadratic interlayer distance dependence. Finally, when only one layer has a mono-vacancy defect, the atomic stress distribution of the pristine layer is affected by the presence of the vacancy. This effect can be considered as a “ghost vacancy” since the deterioration of the pristine layer is similar to that shown by the defective one. These results show that YM of pristine and defective bilayer SNRs could be tailored for a given length and interlayer distance. It is also found that the fracture stress and the fracture strain of defective bilayers are both smaller than those obtained for the defect-free ones. read less NOT USED (high confidence) S. Goel and A. Stukowski, “Comment on ‘Incipient plasticity of diamond during nanoindentation’ by C. Xu, C. Liu and H. Wang, RSC Advances, 2017, 7, 36093,” RSC Advances. 2018. link Times cited: 4 Abstract: A recent molecular dynamics simulation study on nanoindentat… read moreAbstract: A recent molecular dynamics simulation study on nanoindentation of diamond carried out by Xu et al.1 has reported observation of the presence of a controversial hexagonal lonsdaleite phase of carbon in the indentation area. In this comment, we question the reported observation and attribute this anomaly to shortcomings of the long range bond order potential (LCBOP) employed in the nanoindentation study. read less NOT USED (high confidence) A. Aghajamali, C. de Tomas, I. Suarez-Martinez, and N. Marks, “Unphysical nucleation of diamond in the extended cutoff Tersoff potential,” Molecular Simulation. 2018. link Times cited: 8 Abstract: In simulations of carbon materials it is common practice to … read moreAbstract: In simulations of carbon materials it is common practice to view the coefficients of the cutoff function as free parameters which can be optimised according to the system of interest. This work examines a common modification to the widely used Tersoff potential in which the coefficient of the upper cutoff is increased to improve the properties of amorphous carbon. Using molecular dynamics simulations, we show that this so-called extended cutoff Tersoff model leads to nucleation of diamond nanocrystals during annealing of amorphous carbon. By varying the density of the system, and examining the radial distribution function in conjunction with the modified cutoff function, we demonstrate that this behaviour is unphysical, and does not represent a new pathway for synthesising diamond. Viewed from a broader perspective, this observation provides a cautionary tale against altering the parameters of empirical potentials without fully considering the wider implications. read less NOT USED (high confidence) B. Bhattarai, A. Pandey, and D. A. Drabold, “Evolution of amorphous carbon across densities: An inferential study,” Carbon. 2017. link Times cited: 37 NOT USED (high confidence) V. Dozhdikov, A. Basharin, P. Levashov, and D. Minakov, “Atomistic simulations of the equation of state and hybridization of liquid carbon at a temperature of 6000 K in the pressure range of 1-25 GPa.,” The Journal of chemical physics. 2017. link Times cited: 16 Abstract: The equation of state and the structure of liquid carbon are… read moreAbstract: The equation of state and the structure of liquid carbon are studied by molecular simulation. Both classical and quantum molecular dynamics (QMD) are used to calculate the equation of state and the distribution of chemical bonds at 6000 K in the pressure range 1-25 GPa. Our calculations and results of other authors show that liquid carbon has a fairly low density on the order of 1.2-1.35 g/cm3 at pressures about 1 GPa. Owing to the coordination number analysis, this fact can be attributed to the high content of sp1-bonded atoms (more than 50% according to our ab initio computations). Six empirical potentials have been tested in order to describe the density dependence of pressure and structure at 6000 K. As a result, only one potential, ReaxFF/lg, was able to reproduce the QMD simulations for both the equation of state and the fraction of sp1, sp2, sp3-bonded atoms. read less NOT USED (high confidence) M. Thompson et al., “An Atomistic Carbide-Derived Carbon Model Generated Using ReaxFF-Based Quenched Molecular Dynamics.” 2017. link Times cited: 21 Abstract: We report a novel atomistic model of carbide-derived carbons… read moreAbstract: We report a novel atomistic model of carbide-derived carbons (CDCs), which are nanoporous carbons with high specific surface areas, synthesis-dependent degrees of graphitization, and well-ordered, tunable porosities. These properties make CDCs viable substrates in several energy-relevant applications, such as gas storage media, electrochemical capacitors, and catalytic supports. These materials are heterogenous, non-ideal structures and include several important parameters that govern their performance. Therefore, a realistic model of the CDC structure is needed in order to study these systems and their nanoscale and macroscale properties with molecular simulation. We report the use of the ReaxFF reactive force field in a quenched molecular dynamics routine to generate atomistic CDC models. The pair distribution function, pore size distribution, and adsorptive properties of this model are reported and corroborated with experimental data. Simulations demonstrate that compressing the system after quenching changes the pore size distribution to better match the experimental target. Ring size distributions of this model demonstrate the prevalence of non-hexagonal carbon rings in CDCs. These effects may contrast the properties of CDCs against those of activated carbons with similar pore size distributions and explain higher energy densities of CDC-based supercapacitors. read less NOT USED (high confidence) V. Zalizniak and O. A. Zolotov, “Efficient embedded atom method interatomic potential for graphite and carbon nanostructures,” Molecular Simulation. 2017. link Times cited: 5 Abstract: A new interatomic potential for graphite and graphene based … read moreAbstract: A new interatomic potential for graphite and graphene based on embedded atom method is proposed in this paper. Potential parameters were determined by fitting to the equilibrium lattice constants, the binding energy, the vacancy formation energy and elastic constants. The agreement between the calculated properties of graphite and experimental data is very good. In addition, the proposed potential quite accurately reproduces the surface energy of graphite and the binding energies of carbon atom in fullerene C60 and in SWNTs. The proposed potential is computationally more efficient than the existing widely used carbon potentials. It is intended for use in large-scale molecular dynamics simulations of carbon structures. read less NOT USED (high confidence) R. Ranganathan, S. Rokkam, T. Desai, and P. Keblinski, “Generation of amorphous carbon models using liquid quench method: A reactive molecular dynamics study,” Carbon. 2017. link Times cited: 66 NOT USED (high confidence) C. Tomas, I. Suarez-Martinez, and N. Marks, “Graphitization of amorphous carbons: A comparative study of interatomic potentials,” Carbon. 2016. link Times cited: 160 NOT USED (high confidence) A. H. Farmahini and S. Bhatia, “Effect of structural anisotropy and pore-network accessibility on fluid transport in nanoporous Ti3SiC2 carbide-derived carbon,” Carbon. 2016. link Times cited: 21 NOT USED (high confidence) Y. Xu, J. Geng, X. Zheng, K. Dearn, and X. Hu, “Friction-Induced Transformation from Graphite Dispersed in Esterified Bio-Oil to Graphene,” Tribology Letters. 2016. link Times cited: 21 NOT USED (high confidence) F. Valencia, J. Mella, R. González, M. Kiwi, and E. Bringa, “Confinement effects in irradiation of nanocrystalline diamond,” Carbon. 2015. link Times cited: 17 NOT USED (high confidence) X. W. Zhou, D. Ward, and M. E. Foster, “An analytical bond‐order potential for carbon,” Journal of Computational Chemistry. 2015. link Times cited: 38 Abstract: Carbon is the most widely studied material today because it … read moreAbstract: Carbon is the most widely studied material today because it exhibits special properties not seen in any other materials when in nano dimensions such as nanotube and graphene. Reduction of material defects created during synthesis has become critical to realize the full potential of carbon structures. Molecular dynamics (MD) simulations, in principle, allow defect formation mechanisms to be studied with high fidelity, and can, therefore, help guide experiments for defect reduction. Such MD simulations must satisfy a set of stringent requirements. First, they must employ an interatomic potential formalism that is transferable to a variety of carbon structures. Second, the potential needs to be appropriately parameterized to capture the property trends of important carbon structures, in particular, diamond, graphite, graphene, and nanotubes. Most importantly, the potential must predict the crystalline growth of the correct phases during direct MD simulations of synthesis to achieve a predictive simulation of defect formation. Because an unlimited number of structures not included in the potential parameterization are encountered, the literature carbon potentials are often not sufficient for growth simulations. We have developed an analytical bond order potential for carbon, and have made it available through the public MD simulation package LAMMPS. We demonstrate that our potential reasonably captures the property trends of important carbon phases. Stringent MD simulations convincingly show that our potential accounts not only for the crystalline growth of graphene, graphite, and carbon nanotubes but also for the transformation of graphite to diamond at high pressure. © 2015 Wiley Periodicals, Inc. read less NOT USED (high confidence) C. D. Latham, A. J. McKenna, T. Trevethan, M. Heggie, M. Rayson, and P. Briddon, “On the validity of empirical potentials for simulating radiation damage in graphite: a benchmark,” Journal of Physics: Condensed Matter. 2015. link Times cited: 23 Abstract: In this work, the ability of methods based on empirical pote… read moreAbstract: In this work, the ability of methods based on empirical potentials to simulate the effects of radiation damage in graphite is examined by comparing results for point defects, found using ab initio calculations based on density functional theory (DFT), with those given by two state of the art potentials: the Environment-Dependent Interatomic Potential (EDIP) and the Adaptive Intermolecular Reactive Empirical Bond Order potential (AIREBO). Formation energies for the interstitial, the vacancy and the Stone–Wales (5775) defect are all reasonably close to DFT values. Both EDIP and AIREBO can thus be suitable for the prompt defects in a cascade, for example. Both potentials suffer from arefacts. One is the pinch defect, where two α-atoms adopt a fourfold-coordinated sp3 configuration, that forms a cross-link between neighbouring graphene sheets. Another, for AIREBO only, is that its ground state vacancy structure is close to the transition state found by DFT for migration. The EDIP fails to reproduce the ground state self-interstitial structure given by DFT, but has nearly the same formation energy. Also, for both potentials, the energy barriers that control diffusion and the evolution of a damage cascade, are not well reproduced. In particular the EDIP gives a barrier to removal of the Stone–Wales defect as 0.9 eV against DFT's 4.5 eV. The suite of defect structures used is provided as supplementary information as a benchmark set for future potentials. read less NOT USED (high confidence) J. Buchan, M. Robinson, H. J. Christie, D. L. Roach, D. Ross, and N. Marks, “Molecular dynamics simulation of radiation damage cascades in diamond,” Journal of Applied Physics. 2015. link Times cited: 32 Abstract: Radiation damage cascades in diamond are studied by molecula… read moreAbstract: Radiation damage cascades in diamond are studied by molecular dynamics simulations employing the Environment Dependent Interaction Potential for carbon. Primary knock-on atom (PKA) energies up to 2.5 keV are considered and a uniformly distributed set of 25 initial PKA directions provide robust statistics. The simulations reveal the atomistic origins of radiation-resistance in diamond and provide a comprehensive computational analysis of cascade evolution and dynamics. As for the case of graphite, the atomic trajectories are found to have a fractal-like character, thermal spikes are absent and only isolated point defects are generated. Quantitative analysis shows that the instantaneous maximum kinetic energy decays exponentially with time, and that the timescale of the ballistic phase has a power-law dependence on PKA energy. Defect recombination is efficient and independent of PKA energy, with only 50% of displacements resulting in defects, superior to graphite where the same quantity is nearly 75%. read less NOT USED (high confidence) N. Marks and M. Robinson, “Variable timestep algorithm for molecular dynamics simulation of non-equilibrium processes,” Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms. 2015. link Times cited: 9 NOT USED (high confidence) A. H. Farmahini, D. Sholl, and S. Bhatia, “Fluorinated carbide-derived carbon: more hydrophilic, yet apparently more hydrophobic.,” Journal of the American Chemical Society. 2015. link Times cited: 16 Abstract: We explore the effect of fluorine doping on hydrophobicity o… read moreAbstract: We explore the effect of fluorine doping on hydrophobicity of nanoporous silicon carbide-derived carbon (SiCDC), and investigate the underlying barriers for adsorption and diffusion of water vapor and CO2 in the fluorinated and nonfluorinated structures. We develop atomistic models of fluorine-doped SiCDC at three different levels of fluorination, based on a hybrid reverse Monte Carlo constructed model of SiCDC, and develop a novel first-principles force field for the simulation of adsorption and transport of water and CO2 in the fluorine-doped carbon materials. We demonstrate an apparent dual effect of fluorination, showing that while fluorination generates more hydrophilic carbon surfaces, they actually act as more hydrophobic structures due to enhanced energy barriers in the disordered network of microporous carbon. While an increase in adsorption energy and in water uptake is seen for fluorine-doped carbon, large internal free energy barriers as well as the results of MD simulations demonstrate that the increased adsorption is kinetically limited and not experimentally observable on practical time scales. We show that an increase in apparent hydrophobicity due to fluorination is mediated by larger free energy barriers arising from stronger binding of fluid molecules inside the pore network, as opposed to repulsion or steric hindrance to the diffusion of molecules through narrow pore entries. For carbon dioxide, adsorption enthalpies and activation energy barriers are both decreased on fluorination, indicating weakened solid-fluid binding energies in the fluorinated systems. read less NOT USED (high confidence) A. H. Farmahini and S. Bhatia, “Hybrid Reverse Monte Carlo simulation of amorphous carbon: Distinguishing between competing structures obtained using different modeling protocols,” Carbon. 2015. link Times cited: 33 NOT USED (high confidence) Y. Shi, “A minimalist’s reactive potential for efficient molecular modelling of chemistry,” Molecular Simulation. 2015. link Times cited: 1 Abstract: We review a minimalist's reactive force field, reactive… read moreAbstract: We review a minimalist's reactive force field, reactive state summation (RSS) potential. The essence of RSS potential scheme is to model each reactive state by individual non-reactive force fields, then modulate each term by a reaction-coordinate-dependent weight function, finally sum together to obtain the reactive potential. Compared with existing reactive potentials, RSS potential is easier to formulate and parameterise and is computationally efficient, at the expense of lesser accuracy. Thus, RSS potential can be regarded as a ‘reactive Lennard-Jones’ potential. Three exemplary RSS potentials are described in the context of their respective chemical systems: RSS-nitrogen for modelling detonation, RSS-carbon for modelling pyrolysis of activated carbon and RSS-fuel-catalyst for modelling catalytic chemical reaction. read less NOT USED (high confidence) P. Kowalczyk, A. Terzyk, P. A. Gauden, S. Furmaniak, and K. Kaneko, “Toward in silico modeling of palladium-hydrogen-carbon nanohorn nanocomposites.,” Physical chemistry chemical physics : PCCP. 2014. link Times cited: 3 Abstract: We present the first in silico modeling of the Pd-H-single-w… read moreAbstract: We present the first in silico modeling of the Pd-H-single-walled carbon nanohorn nanocomposites. Temperature-quench Monte Carlo simulations are used to generate the most stable morphologies of Pd81 clusters (cluster sizes of ∼2 nm) deposited inside the morphologically defective single-walled carbon nanohorns (S. Furmaniak, A. P. Terzyk, K. Kaneko, P. A. Gauden, P. Kowalczyk, T. Itoh, Phys. Chem. Chem. Phys., 2013, 15, 1232-1240). The optimized Pd81-single-walled carbon nanohorn nanocomposites are next used in calculating the H binding energy distributions at 300 K. The most stable positions of H impurity in confined Pd81 clusters are identified, showing subsurface character of H absorption from the dilute H2 gas at 300 K. The H binding energy distribution on the Pd(100) open surface at 300 K is computed and compared with those corresponding to Pd81-single-walled carbon nanohorn nanocomposites. Finally, the impact of the Pd-H short-range order on the H binding energy is explored and critically discussed. read less NOT USED (high confidence) J.-M. Leyssale and G. Vignoles, “A Large-Scale Molecular Dynamics Study of the Divacancy Defect in Graphene,” Journal of Physical Chemistry C. 2014. link Times cited: 39 Abstract: We report on the dynamical behavior of single divacancy defe… read moreAbstract: We report on the dynamical behavior of single divacancy defects in large graphene sheets as studied by extensive classical molecular dynamics (MD) simulations at high temperatures and static calculations. In the first part of the paper, the ability of the used interatomic potential to properly render the stability and dynamics (energy barriers) of such defects is validated against electronic structure calculations from the literature. Then, results from MD simulations are presented. In agreement with recent TEM studies, some mobility is observed through a series of Stone–Wales-like bond rotations involving the 5–8–5, 555–777, and 5555–6–7777 reconstructions. Although these three structures are by far the most probable structures of the DV defect, not less than 18 other full reconstructions, including the experimentally observed 55–66–77 defect, were occasionally observed in the ≈1.5 μs of MD trajectories analyzed in this work. Most of these additional reconstructions have moderate formation energies and c... read less NOT USED (high confidence) C. Ricolleau, Y. Bouar, H. Amara, O. Landon-Cardinal, and D. Alloyeau, “Random vs realistic amorphous carbon models for high resolution microscopy and electron diffraction,” Journal of Applied Physics. 2013. link Times cited: 21 Abstract: Amorphous carbon and amorphous materials in general are of p… read moreAbstract: Amorphous carbon and amorphous materials in general are of particular importance for high resolution electron microscopy, either for bulk materials, generally covered with an amorphous layer when prepared by ion milling techniques, or for nanoscale objects deposited on amorphous substrates. In order to quantify the information of the high resolution images at the atomic scale, a structural modeling of the sample is necessary prior to the calculation of the electron wave function propagation. It is thus essential to be able to reproduce the carbon structure as close as possible to the real one. The approach we propose here is to simulate a realistic carbon from an energetic model based on the tight-binding approximation in order to reproduce the important structural properties of amorphous carbon. At first, we compare this carbon with the carbon obtained by randomly generating the carbon atom positions. In both cases, we discuss the limit thickness of the phase object approximation. In a second step, we show the influence of both carbons models on (i) the contrast of Cu, Ag, and Au single atoms deposited on carbon and (ii) the determination of the long-range order parameter in CoPt bimetallic nanoalloys. read less NOT USED (high confidence) A. Mrugalla and J. Schnack, “Classical molecular dynamics investigations of biphenyl-based carbon nanomembranes,” Beilstein Journal of Nanotechnology. 2013. link Times cited: 9 Abstract: Summary Background: Free-standing carbon nanomembranes (CNM)… read moreAbstract: Summary Background: Free-standing carbon nanomembranes (CNM) with molecular thickness and macroscopic size are fascinating objects both for fundamental reasons and for applications in nanotechnology. Although being made from simple and identical precursors their internal structure is not fully known and hard to simulate due to the large system size that is necessary to draw definite conclusions. Results: We performed large-scale classical molecular dynamics investigations of biphenyl-based carbon nanomembranes. We show that one-dimensional graphene-like stripes constitute a highly symmetric quasi one-dimensional energetically favorable ground state. This state does not cross-link. Instead cross-linked structures are formed from highly excited precursors with a sufficient amount of broken phenyls. Conclusion: The internal structure of the CNM is very likely described by a disordered metastable state which is formed in the energetic initial process of electron irradiation and depends on the process of relaxation into the sheet phase. read less NOT USED (high confidence) R. Powles, N. Marks, D. Lau, D. McCulloch, and D. Mckenzie, “An energy landscape for carbon network solids,” Carbon. 2013. link Times cited: 8 NOT USED (high confidence) G. Opletal, T. Petersen, I. Snook, and S. Russo, “HRMC_2.0: Hybrid Reverse Monte Carlo method with silicon, carbon and germanium potentials,” Comput. Phys. Commun. 2013. link Times cited: 24 NOT USED (high confidence) A. H. Farmahini, G. Opletal, and S. Bhatia, “Structural modelling of silicon carbide-derived nanoporous carbon by hybrid reverse Monte Carlo simulation,” Journal of Physical Chemistry C. 2013. link Times cited: 59 Abstract: An atomistic model of the nanoparticle size Silicon Carbide … read moreAbstract: An atomistic model of the nanoparticle size Silicon Carbide Derived Carbon (SiC-CDC) is constructed using the Hybrid Reverse Monte Carlo (HRMC) simulation technique through a two-step modeling procedure. Pore volume and three-membered ring constraints are utilized in addition to the commonly used structure factor and energy constraints in the HRMC modeling to overcome the challenges arising from uncertainties involved in determining the structure. The final model is characterized for its important structural features including pore volume, surface area, pore size distribution, physical pore accessibility, and structural defects. It is shown that the microporous structure of SiC-CDC 800 possesses a high pore volume and surface area, making it potentially a good candidate for gas adsorption applications. The HRMC model reveals the SiC-CDC 800 structure to be highly amorphous, largely comprising twisted graphene sheets. It is found that these distorted graphene-like carbon sheets comprising the carbon struct... read less NOT USED (high confidence) N. Pineau, “Molecular Dynamics Simulations of Shock Compressed Graphite,” Journal of Physical Chemistry C. 2013. link Times cited: 27 Abstract: We present molecular dynamic simulations of the shock compre… read moreAbstract: We present molecular dynamic simulations of the shock compression of graphite with the LCBOPII potential. The range of shock intensities covers the full range of available experimental data, including near-terapascal pressures. The results are in excellent agreement with the available DFT data and point to a graphite-diamond transition for shock pressures above 65 GPa, a value larger than the experimental data (20 to 50 GPa). The transition mechanism leads preferentially to hexagonal diamond through a diffusionless process but is submitted to irreversible regraphitization upon release: this result is in good agreement with the lack of highly ordered diamond observed in post-mortem experimental samples. Melting is found for shock pressures ranging from 200 to 300 GPa, close to the approximate LCBOPII diamond melting line. A good overall agreement is found between the calculated and experimental Hugoniot data up to 46% compression rate. read less NOT USED (high confidence) R. Dey, S. K. Deshpande, S. B. Singh, N. Chand, D. Patil, and S. Kulkarni, “X-ray reflectivity study of bias graded diamond like carbon film synthesized by ECR plasma,” Bulletin of Materials Science. 2013. link Times cited: 4 NOT USED (high confidence) S. Furmaniak, “New Virtual Porous Carbons Based on Carbon EDIP Potential and Monte Carlo Simulations,” computational methods in science and technology. 2013. link Times cited: 13 Abstract: Using simple Metropolis Monte Carlo simulations, the series … read moreAbstract: Using simple Metropolis Monte Carlo simulations, the series of virtual porous carbons (VPCs) is generated. During the computations, the carbon EDIP potential is employed. Structures in the series have systematically changing porosity due to the differences in the carbon density. The obtained VPCs are similar to the model proposed by Harris et al., but they do not show its main drawback, because they contain curved fullerene-like sheets, which are interconnected and form one three-dimensional structure. The porosity of VPCs is characterised using a simple geometrical method proposed by Bhattacharya and Gubbins. In order to confirm the reality of the obtained new model carbons and their usefulness for modelling of adsorption phenomena, Monte Carlo simulations of argon adsorption on them are performed. The obtained isotherms are analysed using standard adsorption methods like αs-plots, adsorption potential distributions curves and Dubinin-Astakhov model. The results reveal a close relationship between the systematic changes in the porosity and the adsorption properties. The observed regularities correspond with experimental observations and theoretical studies. read less NOT USED (high confidence) K. Chae, Y. Shi, and L. Huang, “Nanocasting of hierarchical nanostructured porous carbon in molecular dynamics simulation,” Journal of Materials Chemistry. 2013. link Times cited: 14 Abstract: We developed a model template method mimicking the nanocasti… read moreAbstract: We developed a model template method mimicking the nanocasting process by introducing cylindrical templates during the quenched molecular dynamics process [Y. Shi, J. Chem. Phys., 2008, 128, 234707] to generate hierarchical nanostructured porous carbons (HNPCs). Bimodal pore size distributions with both mesopores (from templates) and micropores (from the direct quenching of the carbon source) were well developed during the mimetic nanocasting process. The structure and properties of the nanocast HNPCs can be tailored by various control parameters, such as the template–carbon interaction strength (et), the template radius (rt), the number density of the carbon source (ρ0) and the quench rate (qr). The mesopore wall is made of graphitic carbons, whose morphology can be well-controlled by et and high temperature heat treatments, while the microporous structure can be engineered by ρ0 and qr. The crystallinity of the mesopore wall and the structural integrity of HNPCs (characterized by the number of bridging bonds between the mesopore wall and the microporous region) can be balanced by fine-tuning the control parameters. The mimetic nanocasting method allows us to generate atomic models to quantify the relationship between the structure and properties of HNPCs, and to provide guidelines for identifying the optimal synthesis parameters for HNPCs with desired properties. read less NOT USED (high confidence) J. A. Alonso, I. Cabria, and M. J. López, “Simulation of hydrogen storage in porous carbons,” Journal of Materials Research. 2013. link Times cited: 30 Abstract: Storage is the main problem to use hydrogen as a fuel in the… read moreAbstract: Storage is the main problem to use hydrogen as a fuel in the car industry. Porous carbons are promising storage materials. We have performed computer simulations to investigate carbide-derived porous carbons, showing that these materials exhibit a structure of connected pores with graphitic walls. We then apply a thermodynamic model to evaluate the hydrogen storage. The model accounts for the quantum effects of the motion of the molecules in the pores. The pore widths optimizing the storage depend on pore shape, temperature, and pressure. At 300 K and 10 MPa, the optimal widths lie in the range 6–10 Å. The predictions are consistent with experiment. The calculated storage capacities fall below the targets proposed by the U.S. Department of Energy. This is a consequence of the weak interaction between hydrogen and the pore walls. Metallic doping enhances the binding energy of hydrogen to the walls, which has promising consequences for hydrogen storage. read less NOT USED (high confidence) L. Abbott, K. E. Hart, and C. Colina, “Polymatic: a generalized simulated polymerization algorithm for amorphous polymers,” Theoretical Chemistry Accounts. 2013. link Times cited: 198 NOT USED (high confidence) L. Pastewka, A. Klemenz, P. Gumbsch, and M. Moseler, “Screened empirical bond-order potentials for Si-C,” Physical Review B. 2013. link Times cited: 110 Abstract: Typical empirical bond-order potentials are short ranged and… read moreAbstract: Typical empirical bond-order potentials are short ranged and give ductile instead of brittle behavior for materials such as crystalline silicon or diamond. Screening functions can be used to increase the range of these potentials. We outline a general procedure to combine screening functions with bond-order potentials that does not require to refit any of the potential's properties. We use this approach to modify Tersoff's [Phys. Rev. B 39, 5566 (1989)], Erhart & Albe's [Phys. Rev. B 71, 35211 (2005)] and Kumagai et al.'s [Comp. Mater. Sci. 39, 457 (2007)] Si, C and Si-C potentials. The resulting potential formulations correctly reproduce brittle materials response, and give an improved description of amorphous phases. read less NOT USED (high confidence) L. Pastewka, M. Mrovec, M. Moseler, and P. Gumbsch, “Bond order potentials for fracture, wear, and plasticity,” MRS Bulletin. 2012. link Times cited: 55 Abstract: Coulson’s bond order is a chemically intuitive quantity that… read moreAbstract: Coulson’s bond order is a chemically intuitive quantity that measures the difference in the occupation of bonding and anti-bonding orbitals. Both empirical and rigorously derived bond order expressions have evolved in the course of time and proven very useful for atomistic modeling of materials. The latest generation of empirical formulations has recently been augmented by screening-function approaches. Using friction and wear of diamond and diamond-like carbon as examples, we demonstrate that such a screened bond order scheme allows for a faithful description of dynamical bond-breaking processes in materials far from equilibrium. The rigorous bond order expansions are obtained by systematic coarse-graining of the tight binding approximation and form a bridge between the electronic structure and the atomistic modeling hierarchies. They have enabled bottom-up derivations of bond order potentials for covalently bonded semiconductors, transition metals, and multicomponent intermetallics. The recently developed magnetic bond order potential gives a correct description of both directional covalent bonds and magnetic interactions in iron and is able to correctly predict the stability of bulk Fe polymorphs as well as the intricate properties of dislocation cores. The bond order schemes hence represent a family of reliable and powerful models that can be applied in large-scale simulations of complex processes involving fracture, wear, and plasticity. read less NOT USED (high confidence) D. Duffy, “Modelling materials for fusion power,” International Materials Reviews. 2011. link Times cited: 12 Abstract: Fusion has the potential for delivering safe, clean, low car… read moreAbstract: Fusion has the potential for delivering safe, clean, low carbon power; however, significant scientific and engineering hurdles must first be overcome. One such hurdle is the design of materials that will withstand the harsh conditions. The materials which line the vessel walls will experience exceptionally high heat and particle fluxes, which will gradually erode the materials and contaminate the plasma. The deuterium–tritium fusion reaction will produce high energy neutrons, which will create defects and transmutation reactions in the vessel walls. These defects, along with the transmutation gasses, evolve over time and change the microstructure and properties of the material. In order to design suitable materials for fusion, the radiation damage, and its evolution over time, must be understood and evaluated for a broad class of materials. Modelling has a vital role to play because it can provide details about processes that occur on length and timescales that are inaccessible to experiment. In this review, the challenges that face designers of fusion power plants are discussed. The modelling techniques that are used to model radiation effects are described and the links between modelling and experiment are discussed. The review concludes with a discussion about the future direction for fusion materials research. read less NOT USED (high confidence) P. Ganesh, P. Kent, and V. Mochalin, “Formation, characterization, and dynamics of onion-like carbon structures for electrical energy storage from nanodiamonds using reactive force fields,” Journal of Applied Physics. 2011. link Times cited: 55 Abstract: We simulate the experimentally observed graphitization of na… read moreAbstract: We simulate the experimentally observed graphitization of nanodiamonds into multi-shell onion-like carbon nanostructures, also called carbon onions, at different temperatures, using reactive force fields. The simulations include long-range Coulomb and van der Waals interactions. Our results suggest that long-range interactions play a crucial role in the phase-stability and the graphitization process. Graphitization is both enthalpically and entropically driven and can hence be controlled with temperature. The outer layers of the nanodiamond have a lower kinetic barrier toward graphitization irrespective of the size of the nanodiamond and graphitize within a few-hundred picoseconds, with a large volume increase. The inner core of the nanodiamonds displays a large size-dependent kinetic barrier, and graphitizes much more slowly with abrupt jumps in the internal energy. It eventually graphitizes by releasing pressure and expands once the outer shells have graphitized. The degree of transformation at a partic... read less NOT USED (high confidence) J. Los, C. Bichara, and R. Pellenq, “Tight binding within the fourth moment approximation: Efficient implementation and application to liquid Ni droplet diffusion on graphene.” 2011. link Times cited: 9 Abstract: (Received 8 February 2011; revised manuscript received 13 Ma… read moreAbstract: (Received 8 February 2011; revised manuscript received 13 May 2011; published 31 August 2011)Application of the fourth moment approximation (FMA) to the local density of states within a tight bindingdescription to build a reactive, interatomic interaction potential for use in large scale molecular simulations,is a logical and significant step forward to improve the second moment approximation, standing at the basisof several, widely used (semi-)empirical interatomic interaction models. In this paper we present a sufficientlydetailed description of the FMA and its technical implications, containing the essential elements for an efficientimplementationinasimulationcode.Usingarecent,existingFMA-basedmodelforC-Nisystems,weinvestigatedthesizedependenceofthediffusionofaliquidNiclusteronagraphenesheetandfindapowerlawdependenceofthediffusionconstantontheclustersize(numberofclusteratoms)withanexponentverycloseto−2 read less NOT USED (high confidence) I. Suarez-Martinez and N. Marks, “Effect of microstructure on the thermal conductivity of disordered carbon,” Applied Physics Letters. 2011. link Times cited: 24 Abstract: Computational methods are used to control the degree of stru… read moreAbstract: Computational methods are used to control the degree of structural order in a variety of carbon materials containing primarily sp2 bonding. Room-temperature thermal conductivities are computed using non-equilibrium molecular dynamics. Our results reproduce experimental data for amorphous and glassy carbons and confirm previously proposed structural models for vitreous carbons. An atomistic model is developed for highly oriented thin films seen experimentally, with a maximum computed thermal conductivity of 35 W m−1 K−1. This value is much higher than that of the amorphous and glassy structures, demonstrating that the microstructure influences the thermal conductivity more strongly than the density. read less NOT USED (high confidence) T. Kunze, S. Gemming, M. Posselt, and G. Seifert, “Tribological Aspects of Carbon-Based Nanocoatings – Theory and Simulation,” Zeitschrift für Physikalische Chemie. 2011. link Times cited: 2 Abstract: Nanocoatings have the potential to improve the surface prope… read moreAbstract: Nanocoatings have the potential to improve the surface properties of various materials. They are of extreme importance for surfaces in sliding contact such as highly stressed engine parts. Here, nanocoatings have to be optimized with respect to low friction properties and a high wear resistance to enhance the energetic and environmental efficiency. An important example are diamond-like carbon (DLC) films, which exhibit high mechanical stability depending on their deposition process. We present an introduction to this field of tribology by giving a short overview on DLC films, on the influence of lubricants from a theoretical point of view and in a broader sense, on basic principles of modeling tribological processes with molecular dynamic methods. read less NOT USED (high confidence) I. Suarez-Martinez, P. Higginbottom, and N. Marks, “Molecular dynamics simulations of the transformation of carbon peapods into double-walled carbon nanotubes,” Carbon. 2010. link Times cited: 15 NOT USED (high confidence) F. Jornada, V. Gava, A. L. Martinotto, L. A. Cassol, and C. A. Perottoni, “Modeling of amorphous carbon structures with arbitrary structural constraints,” Journal of Physics: Condensed Matter. 2010. link Times cited: 9 Abstract: In this paper we describe a method to generate amorphous str… read moreAbstract: In this paper we describe a method to generate amorphous structures with arbitrary structural constraints. This method employs the simulated annealing algorithm to minimize a simple yet carefully tailored cost function (CF). The cost function is composed of two parts: a simple harmonic approximation for the energy-related terms and a cost that penalizes configurations that do not have atoms in the desired coordinations. Using this approach, we generated a set of amorphous carbon structures spawning nearly all the possible combinations of sp, sp2 and sp3 hybridizations. The bulk moduli of this set of amorphous carbons structures was calculated using Brenner’s potential. The bulk modulus strongly depends on the mean coordination, following a power-law behavior with an exponent ν = 1.51 ± 0.17. A modified cost function that segregates carbon with different hybridizations is also presented, and another set of structures was generated. With this new set of amorphous materials, the correlation between the bulk modulus and the mean coordination weakens. The method proposed can be easily modified to explore the effects on the physical properties of the presence of hydrogen, dangling bonds, and structural features such as carbon rings. read less NOT USED (high confidence) G. Lucas, M. Bertolus, and L. Pizzagalli, “An environment-dependent interatomic potential for silicon carbide: calculation of bulk properties, high-pressure phases, point and extended defects, and amorphous structures,” Journal of Physics: Condensed Matter. 2010. link Times cited: 41 Abstract: An interatomic potential has been developed to describe inte… read moreAbstract: An interatomic potential has been developed to describe interactions in silicon, carbon and silicon carbide, based on the environment-dependent interatomic potential (EDIP) (Bazant et al 1997 Phys. Rev. B 56 8542). The functional form of the original EDIP has been generalized and two sets of parameters have been proposed. Tests with these two potentials have been performed for many properties of SiC, including bulk properties, high-pressure phases, point and extended defects, and amorphous structures. One parameter set allows us to keep the original EDIP formulation for silicon, and is shown to be well suited for modelling irradiation-induced effects in silicon carbide, with a very good description of point defects and of the disordered phase. The other set, including a new parametrization for silicon, has been shown to be efficient for modelling point and extended defects, as well as high-pressure phases. read less NOT USED (high confidence) T. Kumagai, S. Hara, J. Choi, S. Izumi, and T. Kato, “Development of empirical bond-order-type interatomic potential for amorphous carbon structures,” Journal of Applied Physics. 2009. link Times cited: 21 Abstract: A bond-order-type interatomic potential has been developed f… read moreAbstract: A bond-order-type interatomic potential has been developed for reproducing amorphous carbon (a-C) structures. Several improvements have been incorporated into the conventional Brenner potential so that the material properties of carbon crystals remain unchanged. The main characteristics of the potential function developed in the present research are the use of a screening function instead of a cutoff function and the introduction of a dihedral angle potential around the bond between two threefold coordinated atoms. By using the developed interatomic potential, we can reproduce the material properties of a-C structures, such as the fraction of sp3-bonded atoms, radial distribution function, and ring statistics. It is found that the correction term enhances the formation of cluster structures in a-C, which is confirmed in the first-principles calculation. read less NOT USED (high confidence) Y. Shi, “A mimetic porous carbon model by quench molecular dynamics simulation.,” The Journal of chemical physics. 2008. link Times cited: 65 Abstract: A mimetic porous carbon model is generated using quench mole… read moreAbstract: A mimetic porous carbon model is generated using quench molecular dynamics simulations that reproduces experimental radial distribution functions of activated carbon. The resulting structure is composed of curved and defected graphene sheets. The curvature is induced by nonhexagonal rings. The quench conditions are systematically varied and the final porous structure is scrutinized in terms of its pore size distribution, pore connectivity, and fractal dimension. It is found that the initial carbon density affects the fractal dimension but only causes a minor shift in the pore size distribution. On the other hand, the quench rate affects the pore size distribution but only causes a minor shift in the fractal dimension. read less NOT USED (high confidence) J. Schall, G. Gao, and J. Harrison, “Elastic constants of silicon materials calculated as a function of temperature using a parametrization of the second-generation reactive empirical bond-order potential,” Physical Review B. 2008. link Times cited: 48 Abstract: A parametrization for silicon is presented that is based on … read moreAbstract: A parametrization for silicon is presented that is based on the second-generation reactive empirical bondorder REBO formalism Brenner, Shenderova, Harrison, Stuart, Ni, and Sinnott J. Phys.: Condens. Matter 14, 783 2002 . Because it shares the same analytic form as Brenner’s second-generation REBO, this new potential is a step toward a single potential that can model many atom systems that contain C, Si, and H, where bond breaking and bond making are important. The widespread use of Brenner’s REBO potential, its ability to model both zero-Kelvin elastic constants of diamond and the temperature dependence of the elastic constants, and the existence of parameters for many atom types were the motivating factors for obtaining this parametrization for Si. While Si-C-H classical bond-order potentials do exist, they are based on Brenner’s original formalism. This new parametrization is validated by examining the structure and stability of a large number of crystalline silicon structures, by examining the relaxation energies of point defects, the energies of silicon surfaces, the effects of adatoms on surface energies, and the structures of both liquid silicon and amorphous silicon. Finally, the elastic constants of diamond-cubic and amorphous silicon between 0 and 1100 K are calculated with this new parametrization and compared to values calculated using a previously published potential. read less NOT USED (high confidence) J. Kermode, “Multiscale hybrid simulation of brittle fracture.” 2008. link Times cited: 5 NOT USED (high confidence) J. J. Titantah and D. Lamoen, “The effect of temperature on the structural, electronic and optical properties of sp3-rich amorphous carbon,” Journal of Physics: Condensed Matter. 2008. link Times cited: 12 Abstract: The effect of temperature on the structural, electronic and … read moreAbstract: The effect of temperature on the structural, electronic and optical properties of dense tetrahedral amorphous carbon made of ∼80% sp3-bonded atoms is investigated using a combination of the classical Monte Carlo technique and density functional theory. A structural transformation accompanied by a slight decrease of the sp3 fraction is evidenced above a temperature of about 600 °C. A structural analysis in combination with energy-loss near-edge structure calculations shows that beyond this temperature, the sp2-bonded C sites arrange themselves so as to enhance the conjugation of the π electrons. The Tauc optical band gap deduced from the calculated dielectric function shows major changes beyond this temperature in accordance with experimental results. Energy-loss near-edge structure and band gap calculations additionally reveal a massive destabilization of the of sp3 bonding phase in favour of sp2 bonding at a temperature of about 1300 °C which agrees very well with the reported value of 1100 °C. read less NOT USED (high confidence) S. L. Mielke, T. Belytschko, and G. Schatz, “Nanoscale fracture mechanics.,” Annual review of physical chemistry. 2007. link Times cited: 42 Abstract: Theoretical calculations on undefected nanoscale materials p… read moreAbstract: Theoretical calculations on undefected nanoscale materials predict impressive mechanical properties. In this review we summarize the status of experimental efforts to directly measure the fracture strengths of inorganic and carbon nanotubes and discuss possible explanations for the deviations between the predicted and observed values. We also summarize the role of theory in understanding the molecular-level origin of these deviations. In particular, we consider the role of defects such as vacancies, Stone-Wales defects, adatoms and ad-dimers, chemical functionalization, and oxidative pitting. read less NOT USED (high confidence) N. Marks, M. F. Cover, and C. Kocer, “The importance of rare events in thin film deposition: a molecular dynamics study of tetrahedral amorphous carbon,” Molecular Simulation. 2006. link Times cited: 3 Abstract: The transition of diamond-like materials from an sp3 to sp2 … read moreAbstract: The transition of diamond-like materials from an sp3 to sp2 rich state is of particular interest because of the desirable properties of tetrahedral amorphous carbon (ta-C). Previous works indicate that infrequent processes may dominate this transition, but simulation of these processes presents significant difficulties, since the infrequent processes are activated on the millisecond scale. In this molecular dynamics study the environment dependent interaction potential is used to simulate the thin film deposition of ta-C. Infrequent processes occurring between energetic impacts were activated on the picosecond scale using elevated temperatures. The simulations reveal an abrupt transition in which the ta-C films transform into graphite-like sheets. A similar transformation, albeit at much higher temperatures, is also observed when the films are heated without energetic impacts. These results are found to be in good agreement with published experimental data. read less NOT USED (high confidence) T. X. Nguyen, S. Bhatia, S. Jain, and K. Gubbins, “Structure of saccharose-based carbon and transport of confined fluids: hybrid reverse Monte Carlo reconstruction and simulation studies,” Molecular Simulation. 2006. link Times cited: 43 Abstract: We present results of the reconstruction of a saccharose-bas… read moreAbstract: We present results of the reconstruction of a saccharose-based activated carbon (CS1000a) using hybrid reverse Monte Carlo (HRMC) simulation, recently proposed by Opletal et al. [1]. Interaction between carbon atoms in the simulation is modeled by an environment dependent interaction potential (EDIP) [2,3]. The reconstructed structure shows predominance of sp2 over sp3 bonding, while a significant proportion of sp hybrid bonding is also observed. We also calculated a ring distribution and geometrical pore size distribution of the model developed. The latter is compared with that obtained from argon adsorption at 87 K using our recently proposed characterization procedure [4], the finite wall thickness (FWT) model. Further, we determine self-diffusivities of argon and nitrogen in the constructed carbon as functions of loading. It is found that while there is a maximum in the diffusivity with respect to loading, as previously observed by Pikunic et al. [5], diffusivities in the present work are 10 times larger than those obtained in the prior work, consistent with the larger pore size as well as higher porosity of the activated saccharose carbon studied here. read less NOT USED (high confidence) E. Neyts and A. Bogaerts, “Influence of internal energy and impact angle on the sticking behaviour of reactive radicals in thin a-C:H film growth: a molecular dynamics study.,” Physical chemistry chemical physics : PCCP. 2006. link Times cited: 8 Abstract: In this molecular dynamics study, we investigate the influen… read moreAbstract: In this molecular dynamics study, we investigate the influence of the internal energy and the impact angle on the sticking coefficients of several hydrocarbon radicals on a hydrogenated amorphous carbon surface. The selected radical species and their kinetic energy were determined experimentally. However, no information is available regarding their internal energy, nor on their impact angles. It is shown that the internal energy has a considerable influence on the sticking coefficient, which is dependent on the kind of species. The impact angle, however, is shown to be of minor importance. read less NOT USED (high confidence) B. Ni, K.-H. Lee, and S. Sinnott, “A reactive empirical bond order (REBO) potential for hydrocarbon oxygen interactions,” Journal of Physics: Condensed Matter. 2004. link Times cited: 108 Abstract: The expansion of the second-generation reactive empirical bo… read moreAbstract: The expansion of the second-generation reactive empirical bond order (REBO) potential for hydrocarbons, as parametrized by Brenner and co-workers, to include oxygen is presented. This involves the explicit inclusion of C–O, H–O, and O–O interactions to the existing C–C, C–H, and H–H interactions in the REBO potential. The details of the expansion, including all parameters, are given. The new, expanded potential is then applied to the study of the structure and chemical stability of several molecules and polymer chains, and to modelling chemical reactions among a series of molecules, within classical molecular dynamics simulations. read less NOT USED (high confidence) L. Ghiringhelli, J. Los, E. Meijer, A. Fasolino, and D. Frenkel, “High-pressure diamondlike liquid carbon,” Physical Review B. 2004. link Times cited: 30 Abstract: We report density-functional based molecular-dynamics simula… read moreAbstract: We report density-functional based molecular-dynamics simulations, which show that, with increasing pressure, liquid carbon undergoes a gradual transformation from a liquid with local threefold coordination to a "diamondlike" liquid. We demonstrate that this unusual structural change is well reproduced by an empirical bond-order potential with isotropic long-range interactions, supplemented by torsional terms. In contrast, state-of-the-art short-range bond-order potentials do not reproduce this diamond structure. This suggests that a correct description of long-range interactions is crucial for a unified description of the solid and liquid phases of carbon. read less NOT USED (high confidence) J. Los and A. Fasolino, “Intrinsic long-range bond-order potential for carbon: Performance in Monte Carlo simulations of graphitization,” Physical Review B. 2003. link Times cited: 233 Abstract: We propose a bond order potential for carbon with built-in l… read moreAbstract: We propose a bond order potential for carbon with built-in long-range interactions. The potential is defined as the sum of an angular and coordination dependent short-range part accounting for the strong covalent interactions and a radial long-range part describing the weak interactions responsible, e.g., for the interplanar binding in graphite. The short-range part is a Brenner type of potential, with several modifications introduced to get an improved description of elastic properties and conjugation. Contrary to previous long-range extensions of existing bond order potentials, we prevent the loss of accuracy by compensating for the additional long-range interactions by an appropriate parametrization of the short-range part. We also provide a short-range bond order potential. In Monte Carlo simulations our potential gives a good description of the diamond to graphite transformation. For thin (111) slabs graphitization proceeds perpendicular to the surface as found in ab initio simulations, whereas for thick layers we find that graphitization occurs layer by layer. read less NOT USED (high confidence) A. Barnard, S. Russo, and I. Snook, “Comparative Hartree-Fock and density-functional theory study of cubic and hexagonal diamond,” Philosophical Magazine B. 2002. link Times cited: 27 Abstract: An analysis of the electronic properties of bulk cubic and h… read moreAbstract: An analysis of the electronic properties of bulk cubic and hexagonal diamond calculated using the ab initio packages CRYSTAL98 and the Vienna Ab initio Simulation Package is presented. We apply these ab initio methods to the study of cubic diamond, including the calculation of electronic properties (such as the band structure, electronic density of states, the indirect bandgap E indirect g, the valence band width and the conduction band width) and mechanical properties (such as the equilibrium lattice constant a 0 and the bulk modulus B). The combination of theoretical techniques that yield results that most accurately match experiment for cubic diamond are then used to calculate the electronic properties of the hexagonal diamond polymorph. read less NOT USED (high confidence) A. S. Barnard, S. Russo, and G. Leach, “Nearest neighbour considerations in Stillinger-Weber type potentials for diamond,” Molecular Simulation. 2002. link Times cited: 5 Abstract: Results of a preliminary investigation into the effect of va… read moreAbstract: Results of a preliminary investigation into the effect of varying the interaction cutoff on the bulk properties of diamond using a Stillinger-Weber (SW) type potential for C (Diamond) are presented. The interaction cutoff is varied over a range that includes and excludes the second-nearest neighbours. Whilst the original SW potential for silicon only included first-nearest neighbours inside the interaction cut-off, subsequent parameterizations for carbon (diamond) have also included second-nearest neighbours. Elastic and vibration properties of diamond were calculated over a range of cutoff distances used and the results show that certain lattice properties exhibit an approximately linear dependence on the interaction cut-off. read less NOT USED (high confidence) P. Keblinski, M. Bazant, R. Dash, and M. Treacy, “Thermodynamic behavior of a model covalent material described by the environment-dependent interatomic potential,” Physical Review B. 2002. link Times cited: 38 Abstract: Using molecular-dynamics simulations we study the thermodyna… read moreAbstract: Using molecular-dynamics simulations we study the thermodynamic behavior of a single-component covalent material described by the recently proposed environment-dependent interatomic potential (EDIP). The parametrization of EDIP for silicon exhibits a range of unusual properties typically found in more complex materials, such as the existence of two structurally distinct disordered phases, a density increase upon melting of the low-temperature amorphous phase, and negative thermal-expansion coefficients for both the crystal (at high temperatures) and the amorphous phase (at all temperatures). Structural differences between the two disordered phases also lead to a first-order transition between them, which suggests the existence of a second critical point, as is believed to exist for amorphous forms of frozen water. For EDIP-Si, however, the unusual behavior is associated not only with the open nature of tetrahedral bonding but also with a competition between fourfold (covalent) and fivefold (metallic) coordination. The unusual behavior of the model and its unique ability to simulate the liquid/amorphous transition on molecular-dynamics time scales make it a suitable prototype for fundamental studies of anomalous thermodynamics in disordered systems. read less NOT USED (high confidence) N. C. Cooper, M. S. Fagan, C. Goringe, N. Marks, and D. Mckenzie, “Surface structure and sputtering in amorphous carbon thin films: a tight-binding study of film deposition,” Journal of Physics: Condensed Matter. 2002. link Times cited: 22 Abstract: A tight-binding simulation of the atom-by-atom deposition of… read moreAbstract: A tight-binding simulation of the atom-by-atom deposition of amorphous carbon (a-C) at 100 eV incident energy is presented. More than 500 atoms were deposited. Chains are observed to form on the surface, some of which are sputtered. The good agreement with the experimental sputter frequency data and observation that all such clusters are linear provides strong support for the existence of these chains and the direct emission model of sputtering. The bulk of the grown film is a-C with a tetrahedral bonding fraction of 20%. Experiments have shown that at this incident energy of 100 eV, tetrahedral a-C is the preferred structural form rather than the a-C produced by this simulation. This discrepancy is attributed to the short range of the interatomic potential. read less NOT USED (high confidence) H. J. Christie, M. Robinson, D. L. Roach, D. Ross, I. Suarez-Martinez, and N. Marks, “Simulating radiation damage cascades in graphite,” Carbon. 2015. link Times cited: 48 NOT USED (high confidence) H. Eshet, “Unraveling microscopic origins of complex behavior of carbon and sodium with neural-network potentials.” 2011. link Times cited: 0 Abstract: Understanding complex physicochemical processes in materials… read moreAbstract: Understanding complex physicochemical processes in materials at high pressures and temperatures is of tremendous practical and fundamental importance. Experimental difficulties in accessing such conditions make computer simulations an indispensable tool for studying highpressure high-temperature (HPHT) behavior. However, computer simulations have had only limited success in modeling HPHT materials mainly because of the inadequacy of empirical potentials to describe the interatomic interactions in HPHT phases and the computational expense of ab initio simulations. The main objective of the research performed in this work was to contribute to the understanding of microscopic origins of previously unexplained phenomena in the behavior of high-pressure carbon and sodium using molecular dynamics (MD) simulations. The computational limitations in modeling these elements were circumvented by employing an emerging methodology for the neural-network (NN) representation of ab initio potential energy surfaces. The NN potentials combine the accuracy of a first-principle description of interatomic interactions with the computational efficiency of empirical force fields. The construction of the NN potentials for carbon and sodium performed in this work enabled molecular dynamics (MD) studies of these elements on an unprecedented scale. The results presented here address a number of debated questions about the behavior of highpressure phases of these elements. In particular, the NN potential for carbon was used to perform extensive free-energy simulations of the graphite-diamond coexistence curve that showed that nuclear quantum effects are responsible for the flattening of the curve observed at temperatures below 1000 K. The largescale NN-based study of diamond nucleation from graphite offered new insights into the atomistic mechanism for the direct graphiteto-diamond phase transition. It demonstrated that the transformation is not observed at the graphite-diamond coexistence pressure in the static compression experiments because of the prohibitively large strains accompanying the formation of diamond nuclei. This study also explained the formation of the metastable hexagonal diamond phase instead of the stable cubic phase by showing that the lattice distortions around nuclei of cubic diamond are substantially larger than those around hexagonal diamond nuclei. In the case of sodium, the NN potential was used to perform reconstruction of the phase diagram in the region up to 1000 K and 120 GPa. It also enabled a unique insight into the electronic, structural and dynamical properties of dense sodium. One of the most important finding presented here is a new explanation of the dramatic anomalous drop in the melting teperature of sodium at high pressure. It was discovered that, contrary to the previous reports, the drop in melting temperatures is not a consequence of liquid-liquid phase transitions. Instead, it can be attributed to the screening of interionic interactions by conduction electrons, which at high pressure induces a softening in the short-range repulsion wall. The theoretical models and computational methodologies presented in this thesis offer new opportunities for investigating of complex microscopic processes in a wide range of materials. The findings obtained in this work will have immediate practical implications for understanding various phenomena in the behavior of numerous metals and alloys as well as carbon-based nanomaterials. read less |
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