TriclinicPBCEnergyAndForces_bcc_2atom_Si__TE_310416606864_000
| Title
A single sentence description.
|
Potential energy and atomic forces of periodic, non-orthogonal cell of silicon atoms in a perturbed bcc structure |
|---|---|
| Description | This test computes the potential energy and forces of a periodic triclinic box of silicon atoms. The box dimensions and atomic positions were obtained by perturbing a conventional bcc unit cell at a lattice constant of 3.088 Angstroms (equilibrium LDA-DFT value quoted in H. Balamane, T. Halicioglu, and W. Tiller, Phys. Rev. B 46, 2250 (1992).). Each atomic position was perturbed in a random direction with a magnitude of displacement no greater than 0.5 Angstroms. Each of the three supercell vectors was also perturbed randomly with a magnitude of displacement no greater than 0.5 Angstroms. |
| Species
The supported atomic species.
| Si |
| Disclaimer
A statement of applicability provided by the contributor, informing users of the intended use of this KIM Item.
|
See the test driver source (TriclinicPBCEnergyAndForces__TD_892847239811_000) for required formatting of extended xyz file. This kimspec file was generated automatically using the openkim-pipeline `testgenie` utility along with the template files in the test driver directory. |
| Contributor |
Daniel S. Karls |
| Maintainer |
Daniel S. Karls |
| Published on KIM | 2014 |
| How to Cite | Click here to download this citation in BibTeX format. |
| Funding | Not available |
| Short KIM ID
The unique KIM identifier code.
| TE_310416606864_000 |
| Extended KIM ID
The long form of the KIM ID including a human readable prefix (100 characters max), two underscores, and the Short KIM ID. Extended KIM IDs can only contain alpha-numeric characters (letters and digits) and underscores and must begin with a letter.
| TriclinicPBCEnergyAndForces_bcc_2atom_Si__TE_310416606864_000 |
| Citable Link | https://openkim.org/cite/TE_310416606864_000 |
| KIM Item Type | Test |
| Driver | TriclinicPBCEnergyAndForces__TD_892847239811_000 |
| Properties
Properties as defined in kimspec.edn.
These properties are inhereted from the Test Driver.
| |
| KIM API Version | 1.5 |
| Programming Language(s)
The programming languages used in the code and the percentage of the code written in each one.
| 100.00% Python |
| TriclinicPBCEnergyAndForces_bcc_2atom_Si__TE_310416606864_000.txz | Tar+XZ | Linux and OS X archive |
| TriclinicPBCEnergyAndForces_bcc_2atom_Si__TE_310416606864_000.zip | Zip | Windows archive |
This Test requires a Test Driver. Archives for the Test Driver TriclinicPBCEnergyAndForces__TD_892847239811_000 appear below.
| TriclinicPBCEnergyAndForces__TD_892847239811_000.txz | Tar+XZ | Linux and OS X archive |
| TriclinicPBCEnergyAndForces__TD_892847239811_000.zip | Zip | Windows archive |
Parameters for the ‘new’ potential
This parameterization is optimized for tetrahedral structures of silicon (referred to in the paper as the ‘new’ potential in contrast to an ‘old’ version published two years earlier more suitable for high-pressure phases of silicon. The parameters for the ‘old’ potential were by fitting the model to structural energies calculated using density functional theory within the local-density approximation (LDA). The method used for determining the parameters for the ‘new’ potential is not mentioned explicitly, so we presume that the authors followed the same framework for both of their models. The influence distance parameter \(D\) is not reported originally by the authors, here we use a value of 6 angstroms for reasons of speedup. Also the values of parameters \(B_1\) and \(B_2\) reported in the original article correspond to half of the values given below. This is because in our model, the summation of three-body potential term is implemented more efficiently in an asymmetric manner, while Biswas and Hamann assumed a symmetric form for the three-body potential in their original article.
Table of parameters
| Parameter | Value | Units |
|---|---|---|
| \(A_1\) | \(142.2922\) | \(eV\) |
| \(A_2\) | \(-107.0338\) | \(eV\) |
| \(B_1\) | \(26.0598\) | \(eV\) |
| \(B_2\) | \(1.3441478\) | \(eV\) |
| \(\lambda_1\) | \(0.5200836\) | \(\overset{\circ}{A}^{-2}\) |
| \(\lambda_2\) | \(0.4206931\) | \(\overset{\circ}{A}^{-2}\) |
| \(\alpha_1\) | \(0.3034373\) | \(\overset{\circ}{A}^{-2}\) |
| \(\alpha_2\) | \(0.3191903\) | \(\overset{\circ}{A}^{-2}\) |
| \(r_c\) | \(3.9527357\) | \(\overset{\circ}{A}\) |
| \(\mu\) | \(0.3120580\) | \(\overset{\circ}{A}\) |
| \(D\) | \(6.0\) | \(\overset{\circ}{A}\) |
Representative plots
A plot from the original article depicting the angular variation of the three-body potential for the new classical Si model is shown. The bond lengths were set equal to 2.35 angstroms, which is the equilibrium bond length of Si.
Login to edit Wiki content