| Property Definition (short name)
A common way to refer to the Property Definition. Note there may be multiple Property Definitions with the same short name, to fully distinguish between Property Definitions the full Tag URI must be used (the Property Definition ID).
| crystal-structure-npt |
|---|---|
| Property Definition ID
The full Property Definition identifier using the Tag URI scheme.
| tag:staff@noreply.openkim.org,2023-02-21:property/crystal-structure-npt |
| Title
A brief one-sentence description of this Property Definition.
| Equilibrium crystal structure at a given temperature and stress state |
| Description
A description about this Property Definition.
| Equilibrium structure of a crystal at a given temperature and applied stress. The equilibrium structure is expressed as an AFLOW prototype label and its corresponding free parameters representing the average positions of the constituent atoms. Multiple instances of this property with different free parameters may be reported for a given AFLOW prototype label, representing different local stable or unstable equilibria. There is no guarantee that any instance of this property represents the state of minimum Helmholtz free energy of this system, not even when the configuration space is restricted to the specified crystal prototype label. |
| Contributor
The user or organization who initially contributed this Property Definition.
| ilia |
| Maintainer
The user or organization who currently maintains this Property Definition.
| ilia |
| Creation date
The date the Property Definition was "minted", based on its Tag URI.
| 2023-02-21 |
| Content on GitHub
The following content may be available on GitHub: Property Definition (an EDN file containing the Property Definition Keys listed below); Physics Validator (a script provided by the user for validating that an instance of the Property is physically valid); Property Documentation Wiki (the contents of the Wiki displayed at the bottom of this page).
|
Property Definition Physics Validator Property Documentation Wiki |
| type | float |
|---|---|
| has-unit | true |
| extent | [] |
| required | true |
| description | The average equilibrium 'a' lattice constant of the crystal structure as defined by the AFLOW standard. Relative values of other lattice parameters (if present) are given in the 'parameter-values' key. |
| type | float |
|---|---|
| has-unit | true |
| extent | [6] |
| required | true |
| description | The [xx,yy,zz,yz,xz,xy] components of the prescribed symmetric Cauchy stress tensor. The numerical value of the stress tensor of a test result or reference data may be different due to tolerance, and can be checked by inspecting the output files of the test or the reference data description. The components should be expressed in the same coordinate system as the structure specified by prototype-label and parameter-values, with the orientation of lattice vectors defined in M. J. Mehl et al., Comput. Mater. Sci. 136, S1 (2017). |
| type | string |
|---|---|
| has-unit | false |
| extent | [] |
| required | true |
| description | Prototype label (not including an enumeration suffix) as defined by the AFLOW standard (e.g. 'A_tI4_141_a') for the structure. It is expected that the alphabetically lowest of all equivalent labels is chosen. |
| type | string |
|---|---|
| has-unit | false |
| extent | [":"] |
| required | true |
| description | Element symbols corresponding to the atom types in the stoichiometric formula which appears at the start of the prototype label (e.g. ['Mo','S'] for the AB2 stoichiometric formula, means that the 'A' atom is 'Mo' and the 'B' atom is 'S' for the MoS_2 structure). |
| type | float |
|---|---|
| has-unit | true |
| extent | [] |
| required | true |
| description | Temperature of the crystal. |
| type | file |
|---|---|
| has-unit | false |
| extent | [] |
| required | false |
| description | A file containing the average atomic configuration including information such as the species, x,y,z coordinates of each particle, and periodicity data. |
| type | string |
|---|---|
| has-unit | false |
| extent | [] |
| required | false |
| description | The AFLOW library prototype, if any, matching the equilibrium structure. Prototypes in the AFLOW library are associated with common short names used by the materials community. The library prototype includes an integer enumeration suffix defined by the AFLOW standard when there are multiple parameter values associated with the structure (e.g. 'A_tI4_141_a-001' for 'betaSn'). Because these prototype labels are named according to their original material's conventional chemical formula, they may differ from the 'prototype-label' key, which is expected to be standardized to have the alphabetically lowest possible of all equivalent labels. |
| type | string |
|---|---|
| has-unit | false |
| extent | [":"] |
| required | false |
| description | Names of the parameters other than 'a', if present, corresponding to this AFLOW prototype. These can include lattice parameters from the set {'b/a','c/a','alpha','beta','gamma'} (for the conventional crystal structure defined by lattice parameters a, b, and c and angles alpha, beta, gamma), and coordinates of Wyckoff positions that have a degree of variability labeled as 'x*', 'y*' and 'z*' where the asterisk represents an integer as defined by the AFLOW standard. |
| type | float |
|---|---|
| has-unit | false |
| extent | [":"] |
| required | false |
| description | Equilibrium values for the parameters listed in 'parameter-names' corresponding to the average positions of the atoms. Note that all parameters are dimensionless. |
| type | file |
|---|---|
| has-unit | false |
| extent | [] |
| required | false |
| description | A molecular dynamics restart file containing the instantaneous atomic configuration including information such as the species, x,y,z coordinates of each particle, and periodicity data, as well as velocities. The snapshot should be equilibrated at the prescribed stress and temperature. |
| type | string |
|---|---|
| has-unit | false |
| extent | [":"] |
| required | false |
| description | Commonly used name associated with the 'library-prototype-label' key according to the AFLOW prototype library (e.g. 'Face-Centered Cubic' or 'Molybdenite'). |