Querying KIM Content

Table of Contents

• Overview
• get_available_models
• get_lattice_constant_cubic
• get_lattice_constant_hexagonal
• get_lattice_constant_2Dhexagonal
• get_cohesive_energy_cubic
• get_cohesive_energy_hexagonal
• get_cohesive_energy_2Dhexagonal
• get_elastic_constants_isothermal_cubic
• get_bulk_modulus_isothermal_cubic
• get_bulk_modulus_isothermal_hexagonal
• get_linear_thermal_expansion_coefficient_cubic
• get_intrinsic_stacking_fault_relaxed_energy_fcc
• get_extrinsic_stacking_fault_relaxed_energy_fcc
• get_unstable_stacking_fault_relaxed_energy_fcc
• get_unstable_twinning_fault_relaxed_energy_fcc
• get_surface_energy_ideal_cubic
• get_surface_energy_relaxed_cubic

Overview

The KIM Repository contains model drivers, models, test drivers, tests, verification checks, and reference data, as well as results/errors generated by running models against tests and verification checks. All of these items are inserted into a publicly accessible mongo database hosted at https://query.openkim.org. Since querying mongo directly can be tedious, a set of "simplified queries" have been introduced to facilitate searching for items or specific test results. These are outlined below.

For each simplified query, the python function prototype is shown, followed by a brief description and a link to the KIM Property Definition it corresponds to. Users interested in using these functions directly from python should install the kim-query package. They can also be accessed (1) within LAMMPS using the 'kim query' command or (2) via web request using curl/wget/etc. Examples of all three usages are given for each function, as well as a listing of all input and output parameters.

NOTES:

• All input parameters are arrays enclosed in square brackets. These arrays always contain either double-quoted strings, e.g. ["Al"], or numbers, e.g. [293.15]. Multiple entries should be separated by commas; generally, spaces following commas should be avoided.

• The 'model' parameter indicates which KIM model is used to compute the result. In order to retrieve the result for the latest version of a model, the 3-digit version extension at the end of the KIM ID should be omitted. For example, a value of ["EDIP_JustoBazantKaxiras_1998_Si__MO_958932894036"] will retrieve results computing the latest version of this model. However, if a 3-digit version extension is given, it will be respected: only test results computed using that specific version of the model will be retrieved. Finally, the human-readable prefix in the model ID is discarded, so ["MO_958932894036"] will also query for the latest results of the aforementioned EDIP model.

• The 'method' parameter indicates the test driver (algorithm) used to compute the results being retrieved. As with models, it is generally desirable to omit a specific three-digit version extension, which causes the result computed using the latest version of the test driver to be retrieved. The human-readable prefix of the test driver is also discarded, e.g. ["TD_475411767977"] will query for results computing a KIM test that uses the latest version of the LatticeConstantCubicEnergy__TD_475411767977 test driver.

  For many query functions, there are synonyms for specific KIM IDs to promote readability. For example, for the get_lattice_constant_cubic query, "relaxation" is equivalent to test driver TD_475411767977. Note that when using a synonym, a version is not provided, and so results returned are always for the latest version. The available synonyms are listed in the method table next to their corresponding test driver KIM ID separated by a vertical bar (|).

get_available_models

 get_available_models(species, species_logic=["and"], model_interface=["any"], potential_type=["any"],
     simulator_name=["any"])

Retrieve the latest versions of all models that support a given set of atomic species

Usage Examples

python:

  from kim_query import get_available_models
  get_available_models(["Si","C"], ["any"], ["sm"], ["meam"], ["LAMMPS"])

curl:

  curl --data-urlencode 'species=["Si","C"]'        \
       --data-urlencode 'species_logic=["and"]'     \
       --data-urlencode 'model_interface=["sm"]'    \
       --data-urlencode 'potential_type=["meam"]'   \
       --data-urlencode 'simulator_name=["LAMMPS"]' \
       https://query.openkim.org/api/get_available_models

Parameters

species : array of double-quoted strings

The standard chemical symbol(s) of all atomic species that the models returned must support, e.g. "Al". Case-sensitive.

species_logic : array containing one double-quoted string

Whether the species supported by each model returned must be exactly equal to the species listed ("exact"), or are allowed to support species other than those listed ("and"). Note that the order of elements in the species list is unimportant. (Default: "and")

model_interface : array containing one double-quoted string

KIM API interface used by the models that are to be returned. Specifying "mo" will cause only Portable Models to be returned (which use the Portable Model Interface), while "sm" will cause only Simulator Models to be returned (which use the Simulator Model Interface). If left unspecified, both Portable Models and Simulator Models will be returned. (Default: "any")

potential_type : array of double-quoted strings

Potential type of models that are to be returned. Each model has a single associated potential type, e.g. "eam". If multiple values are given in this argument, models that match any of them will be returned, e.g. ["meam", "adp"] will require that all models returned either have a potential type of "meam" or "adp". The terms provided are case-insensitive. See https://openkim.org/doc/schema/naming-potentials for a list of all current potential types tracked in OpenKIM. (Default: "any")

simulator_name : array of double-quoted strings

Simulators supported by models that are to be returned. For KIM portable models, all simulators are supported and so if model_interface is set to ["mo"], this argument has no effect. However, if that is not the case, and KIM simulator models are allowed to be returned, their corresponding simulator must match one of the entries in this list. The terms provided are case-insensitive. (Default: "any")

Returns

[models] : array containing zero or more double-quoted strings

The latest versions of all models of the specified type(s) that support all of the atomic species given.

get_lattice_constant_cubic

 get_lattice_constant_cubic(model, crystal, species, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['relaxation'])

Retrieve the equilibrium lattice constant of the conventional unit cell of a cubic crystal comprised of one or more species at a given temperature and hydrostatic pressure

KIM Property Definition: structure-cubic-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query a0 get_lattice_constant_cubic crystal=["fcc"] species=["Al"] units=["angstrom"]

python:

  from kim_query import get_lattice_constant_cubic
  get_lattice_constant_cubic(["MO_123629422045_005"], ["fcc"], ["Al"], ["angstrom"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'crystal=["fcc"]'               \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["angstrom"]'            \
       https://query.openkim.org/api/get_lattice_constant_cubic

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the cubic crystal. Currently allowed values are "bcc", "diamond", "fcc", and "sc".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of length supported by GNU units in which the lattice constant will be returned, e.g. "angstrom".

temperature : array containing one float, optional

The temperature at which the equilibrium lattice geometry is computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 0.0)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the equilibrium lattice geometry is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to compute the lattice constant. Currently allowed values are:

Returns

[a] : array containing one float

The lattice constant of the conventional unit cell of the cubic crystal in the requested units.

get_lattice_constant_hexagonal

 get_lattice_constant_hexagonal(model, crystal, species, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['relaxation'])

Retrieve equilibrium lattice constants of the conventional unit cell of a hexagonal crystal comprised of one or more species at a given temperature and hydrostatic pressure

KIM Property Definition: structure-hexagonal-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_Mendelev_2007_Zr__MO_848899341753_000 metal
  kim query latconst split get_lattice_constant_hexagonal crystal=["hcp"] species=["Zr"] units=["angstrom"]

python:

  from kim_query import get_lattice_constant_hexagonal
  get_lattice_constant_hexagonal(["MO_848899341753_000"], ["hcp"], ["Zr"], ["angstrom"])

curl:

  curl --data-urlencode 'model=["MO_848899341753_000"]' \
       --data-urlencode 'crystal=["hcp"]'               \
       --data-urlencode 'species=["Zr"]'                \
       --data-urlencode 'units=["angstrom"]'            \
       https://query.openkim.org/api/get_lattice_constant_hexagonal

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the hexagonal crystal. Currently allowed values are "graphite", "hcp", and "sh".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of length supported by GNU units in which the lattice constants will be returned, e.g. "angstrom".

temperature : array containing one float, optional

The temperature at which the equilibrium lattice geometry is computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 0.0)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the equilibrium lattice geometry is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to compute the lattice constants. Currently allowed values are:

Returns

[a, c] : array containing two floats

The lattice constants of the conventional unit cell of the hexagonal crystal in the requested units.

get_lattice_constant_2Dhexagonal

 get_lattice_constant_2Dhexagonal(model, crystal, species, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['relaxation'])

Retrieve equilibrium lattice constant of the conventional unit cell of a 2D hexagonal crystal comprised of one or more species at a given temperature and hydrostatic pressure

KIM Property Definition: structure-2d-hexagonal-crystal-npt

Usage Examples

LAMMPS:

  kim init Tersoff_LAMMPS_Tersoff_1988_C__MO_579868029681_002 metal
  kim query a0 get_lattice_constant_2Dhexagonal crystal=["graphene-like"] species=["C"] units=["angstrom"]

python:

  from kim_query import get_lattice_constant_2Dhexagonal
  get_lattice_constant_2Dhexagonal(["MO_579868029681_002"], ["graphene-like"], ["C"], ["angstrom"])

curl:

  curl --data-urlencode 'model=["MO_579868029681_002"]' \
       --data-urlencode 'crystal=["graphene-like"]'     \
       --data-urlencode 'species=["C"]'                 \
       --data-urlencode 'units=["angstrom"]'            \
       https://query.openkim.org/api/get_lattice_constant_2Dhexagonal

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the 2D hexagonal crystal. Currently, a single value is allowed: "graphene-like".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the 2D crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of length supported by GNU units in which the lattice constant will be returned, e.g. "angstrom".

temperature : array containing one float, optional

The temperature at which the equilibrium lattice geometry is computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 0.0)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the equilibrium lattice geometry is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to compute the lattice constant. Currently allowed values are:

Returns

[a] : array containing one float

The lattice constant of the conventional unit cell of the 2D hexagonal crystal in the requested units.

get_cohesive_energy_cubic

 get_cohesive_energy_cubic(model, crystal, species, units, method=['relaxation'])

Retrieve cohesive energy of a cubic crystal comprised of one or more species at zero temperature and pressure

KIM Property Definition: cohesive-potential-energy-cubic-crystal

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query Ec get_cohesive_energy_cubic crystal=["fcc"] species=["Al"] units=["eV"]

python:

  from kim_query import get_cohesive_energy_cubic
  get_cohesive_energy_cubic(["MO_123629422045_005"], ["fcc"], ["Al"], ["eV"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'crystal=["fcc"]'               \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["eV"]'                  \
       https://query.openkim.org/api/get_cohesive_energy_cubic

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the cubic crystal. Currently allowed values are "bcc", "diamond", "fcc", and "sc".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of energy supported by GNU units in which the cohesive energy will be returned, e.g. "eV".

method : array containing one double-quoted string, optional

The algorithm used to compute the cohesive energy. Currently allowed values are:

Returns

[cohesive_energy] : array containing one float

The cohesive energy in the requested units. This is the IUPAC definition, i.e. a stable crystal will have a positive cohesive energy.

get_cohesive_energy_hexagonal

 get_cohesive_energy_hexagonal(model, crystal, species, units, method=['relaxation'])

Retrieve cohesive energy of a hexagonal crystal comprised of one or more species at zero temperature and pressure

KIM Property Definition: cohesive-potential-energy-hexagonal-crystal

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_Mendelev_2007_Zr__MO_848899341753_000 metal
  kim query Ec get_cohesive_energy_hexagonal crystal=["hcp"] species=["Zr"] units=["eV"]

python:

  from kim_query import get_cohesive_energy_hexagonal
  get_cohesive_energy_hexagonal(["MO_848899341753_000"], ["hcp"], ["Zr"], ["eV"])

curl:

  curl --data-urlencode 'model=["MO_848899341753_000"]' \
       --data-urlencode 'crystal=["hcp"]'               \
       --data-urlencode 'species=["Zr"]'                \
       --data-urlencode 'units=["eV"]'                  \
       https://query.openkim.org/api/get_cohesive_energy_hexagonal

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the hexagonal crystal. Currently allowed values are "graphite", "hcp", and "sh".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of energy supported by GNU units in which the cohesive energy will be returned, e.g. "eV".

method : array containing one double-quoted string, optional

The algorithm used to compute the cohesive energy. Currently allowed values are:

Returns

[cohesive_energy] : array containing one float

The cohesive energy in the requested units. This is the IUPAC definition, i.e. a stable crystal will have a positive cohesive energy.

get_cohesive_energy_2Dhexagonal

 get_cohesive_energy_2Dhexagonal(model, crystal, species, units, method=['relaxation'])

Retrieve cohesive energy of a 2D hexagonal crystal comprised of one or more species at zero temperature and pressure

KIM Property Definition: cohesive-potential-energy-2d-hexagonal-crystal

Usage Examples

LAMMPS:

  kim init Tersoff_LAMMPS_Tersoff_1988_C__MO_579868029681_002 metal
  kim query Ec get_cohesive_energy_2Dhexagonal crystal=["graphene-like"] species=["C"] units=["eV"]

python:

  from kim_query import get_cohesive_energy_2Dhexagonal
  get_cohesive_energy_2Dhexagonal(["MO_579868029681_002"], ["graphene-like"], ["C"], ["eV"])

curl:

  curl --data-urlencode 'model=["MO_579868029681_002"]' \
       --data-urlencode 'crystal=["graphene-like"]'     \
       --data-urlencode 'species=["C"]'                 \
       --data-urlencode 'units=["eV"]'                  \
       https://query.openkim.org/api/get_cohesive_energy_2Dhexagonal

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the hexagonal crystal. Currently, only a single value is allowed: "graphene-like".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of energy supported by GNU units in which the cohesive energy will be returned, e.g. "eV".

method : array containing one double-quoted string, optional

The algorithm used to compute the cohesive energy. Currently allowed values are:

Returns

[cohesive_energy] : array containing one float

The cohesive energy in the requested units. This is the IUPAC definition, i.e. a stable crystal will have a positive cohesive energy.

get_elastic_constants_isothermal_cubic

 get_elastic_constants_isothermal_cubic(model, crystal, species, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['finite-difference'])

Retrieve isothermal elastic constants of a cubic crystal comprised of one or more species at a given temperature and hydrostatic pressure

KIM Property Definition: elastic-constants-isothermal-cubic-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query elastconst split get_elastic_constants_isothermal_cubic crystal=["fcc"] species=["Al"] units=["GPa"]

python:

  from kim_query import get_elastic_constants_isothermal_cubic
  get_elastic_constants_isothermal_cubic(["MO_123629422045_005"], ["fcc"], ["Al"], ["GPa"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'crystal=["fcc"]'               \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["GPa"]'                 \
       https://query.openkim.org/api/get_elastic_constants_isothermal_cubic

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the cubic crystal. Currently allowed values are "bcc", "diamond", "fcc", and "sc".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of pressure supported by GNU units in which the elastic constants will be returned, e.g. "GPa".

temperature : array containing one float, optional

The temperature at which the equilibrium elastic constants are computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 0.0)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the elastic constants are computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple results are found which match the specified pressure within this tolerance, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to compute the elastic constants. Currently allowed values are:

Returns

[c11, c12, c44] : array containing three floats

The isothermal cubic elastic constants in the requested units.

get_bulk_modulus_isothermal_cubic

 get_bulk_modulus_isothermal_cubic(model, crystal, species, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['finite-difference'])

Retrieve isothermal bulk modulus of a cubic crystal comprised of one or more species at a given temperature and hydrostatic pressure

KIM Property Definition: bulk-modulus-isothermal-cubic-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query B get_bulk_modulus_isothermal_cubic crystal=["fcc"] species=["Al"] units=["GPa"]

python:

  from kim_query import get_bulk_modulus_isothermal_cubic
  get_bulk_modulus_isothermal_cubic(["MO_123629422045_005"], ["fcc"], ["Al"], ["GPa"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'crystal=["fcc"]'               \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["GPa"]'                 \
       https://query.openkim.org/api/get_bulk_modulus_isothermal_cubic

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the cubic crystal. Currently allowed values are "bcc", "diamond", "fcc", and "sc".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of pressure supported by GNU units in which the bulk modulus will be returned, e.g. "GPa".

temperature : array containing one float, optional

The temperature at which the bulk modulus is computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 0.0)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the bulk modulus is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to compute the isothermal bulk modulus. Currently allowed values are:

Returns

[B] : array containing one float

The isothermal bulk modulus in the requested units.

get_bulk_modulus_isothermal_hexagonal

 get_bulk_modulus_isothermal_hexagonal(model, crystal, species, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['finite-difference'])

Retrieve isothermal bulk modulus of a hexagonal crystal comprised of one or more species at zero temperature and pressure

KIM Property Definition: bulk-modulus-isothermal-hexagonal-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_Mendelev_2007_Zr__MO_848899341753_000 metal
  kim query B get_bulk_modulus_isothermal_hexagonal crystal=["hcp"] species=["Zr"] units=["GPa"]

python:

  from kim_query import get_bulk_modulus_isothermal_hexagonal
  get_bulk_modulus_isothermal_hexagonal(["MO_848899341753_000"], ["hcp"], ["Zr"], ["GPa"])

curl:

  curl --data-urlencode 'model=["MO_848899341753_000"]' \
       --data-urlencode 'crystal=["hcp"]'               \
       --data-urlencode 'species=["Zr"]'                \
       --data-urlencode 'units=["GPa"]'                 \
       https://query.openkim.org/api/get_bulk_modulus_isothermal_hexagonal

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the hexagonal crystal. Currently allowed values are "graphite", "hcp", and "sh".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of pressure supported by GNU units in which the bulk modulus will be returned, e.g. "GPa".

temperature : array containing one float, optional

The temperature at which the bulk modulus is computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 0.0)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the bulk modulus is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to compute the isothermal bulk modulus. Currently allowed values are:

Returns

[B] : array containing one float

The isothermal bulk modulus in the requested units.

get_linear_thermal_expansion_coefficient_cubic

 get_linear_thermal_expansion_coefficient_cubic(model, crystal, species, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['md-volume-expansion'])

Retrieve linear coefficient of thermal expansion of a cubic crystal comprised of one or more species at a given temperature and hydrostatic pressure, calculated according to (change-in-length)/(original-length)/(change-in-temperature)

KIM Property Definition: linear-thermal-expansion-coefficient-cubic-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query alpha get_linear_thermal_expansion_coefficient_cubic crystal=["fcc"] species=["Al"] units=["1/K"] temperature=[293.15] temperature_units=["K"]

python:

  from kim_query import get_linear_thermal_expansion_coefficient_cubic
  get_linear_thermal_expansion_coefficient_cubic(["MO_123629422045_005"], ["fcc"], ["Al"], ["1/K"], [293.15])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'crystal=["fcc"]'               \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["1/K"]'                 \
       --data-urlencode 'temperature=[293.15]'          \
       https://query.openkim.org/api/get_linear_thermal_expansion_coefficient_cubic

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the cubic crystal. Currently allowed values are "bcc", "diamond", "fcc", and "sc".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of 1/temperature supported by GNU units in which the bulk modulus will be returned, e.g. "1/K".

temperature : array containing one float, optional

The temperature at which the linear thermal expansion coefficient is to be computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 293.15)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the linear thermal expansion coefficient is to be computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to compute the linear thermal expansion coefficient. Currently allowed values are:

Returns

[alpha] : array containing one float

The linear thermal expansion coefficient in the requested units.

get_intrinsic_stacking_fault_relaxed_energy_fcc

 get_intrinsic_stacking_fault_relaxed_energy_fcc(model, species, units, pressure=[0.0],
     pressure_units=['MPa'], pressure_tol=[0.1], method=['relaxation'])

Retrieve relaxed intrinsic stacking fault (ISF) energy for a face-centered monoatomic cubic crystal at zero temperature and a specified pressure. The ISF corresponds to a fault of the form ABC|BCA. Relaxation of the atomic coordinates is performed in the direction perpendicular to the fault plane

KIM Property Definition: intrinsic-stacking-fault-relaxed-energy-fcc-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query Estack_intr get_intrinsic_stacking_fault_relaxed_energy_fcc species=["Al"] units=["eV/angstrom^2"]

python:

  from kim_query import get_intrinsic_stacking_fault_relaxed_energy_fcc
  get_intrinsic_stacking_fault_relaxed_energy_fcc(["MO_123629422045_005"], ["Al"], ["eV/angstrom^2"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["eV/angstrom^2"]'       \
       https://query.openkim.org/api/get_intrinsic_stacking_fault_relaxed_energy_fcc

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

species : array containing one string

The standard chemical symbol of the single atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of energy per unit area supported by GNU units in which the relaxed intrinsic stacking fault energy will be returned, e.g. "eV/angstrom^2".

pressure : array containing one float, optional

The pressure at which the relaxed stacking fault energy is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to relax the atomic positions in order to compute the relaxed intrinsic stacking fault energy for a given lattice constant. Currently allowed values are:

Returns

[intrinsic_stacking_fault_energy] : array containing one float

The relaxed intrinsic stacking fault energy of the monoatomic FCC crystal in the requested units.

get_extrinsic_stacking_fault_relaxed_energy_fcc

 get_extrinsic_stacking_fault_relaxed_energy_fcc(model, species, units, pressure=[0.0],
     pressure_units=['MPa'], pressure_tol=[0.1], method=['relaxation'])

Retrieve relaxed extrinsic stacking fault (ESF) energy for a face-centered monoatomic cubic crystal at zero temperature and a specified pressure. The ESF corresponds to an ABC|BA|BC stacking, which can also be understood as a two-layer twin nucleus. Relaxation of the atomic coordinates is performed in the direction perpendicular to the fault plane

KIM Property Definition: extrinsic-stacking-fault-relaxed-energy-fcc-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query Estack_extr get_extrinsic_stacking_fault_relaxed_energy_fcc species=["Al"] units=["eV/angstrom^2"]

python:

  from kim_query import get_extrinsic_stacking_fault_relaxed_energy_fcc
  get_extrinsic_stacking_fault_relaxed_energy_fcc(["MO_123629422045_005"], ["Al"], ["eV/angstrom^2"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["eV/angstrom^2"]'       \
       https://query.openkim.org/api/get_extrinsic_stacking_fault_relaxed_energy_fcc

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

species : array containing one string

The standard chemical symbol of the single atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of energy per unit area supported by GNU units in which the relaxed intrinsic stacking fault energy will be returned, e.g. "eV/angstrom^2".

pressure : array containing one float, optional

The pressure at which the relaxed stacking fault energy is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to relax the atomic positions in order to compute the relaxed extrinsic stacking fault energy for a given lattice constant. Currently allowed values are:

Returns

[extrinsic_stacking_fault_energy] : array containing one float

The relaxed extrinsic stacking fault energy of the monoatomic FCC crystal in the requested units.

get_unstable_stacking_fault_relaxed_energy_fcc

 get_unstable_stacking_fault_relaxed_energy_fcc(model, species, units, pressure=[0.0],
     pressure_units=['MPa'], pressure_tol=[0.1], method=['relaxation'])

Retrieve the relaxed unstable stacking fault energy (USFE) of a face-centered monoatomic cubic crystal at zero temperature and a specified pressure. The USFE corresponds to the energy barrier for rigidly slipping one-half of an infinite crystal relative to the other along a <112> direction (fcc partial dislocation direction). Relaxation of the atomic positions is performed perpendicular to the fault plane.

KIM Property Definition: unstable-stacking-fault-relaxed-energy-fcc-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query Estack_unstable get_unstable_stacking_fault_relaxed_energy_fcc species=["Al"] units=["eV/angstrom^2"]

python:

  from kim_query import get_unstable_stacking_fault_relaxed_energy_fcc
  get_unstable_stacking_fault_relaxed_energy_fcc(["MO_123629422045_005"], ["Al"], ["eV/angstrom^2"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["eV/angstrom^2"]'       \
       https://query.openkim.org/api/get_unstable_stacking_fault_relaxed_energy_fcc

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

species : array containing one string

The standard chemical symbol of the single atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of energy per unit area supported by GNU units in which the relaxed intrinsic stacking fault energy will be returned, e.g. "eV/angstrom^2".

pressure : array containing one float, optional

The pressure at which the relaxed unstable stacking fault energy is to be computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to relax the atomic positions in order to compute the unstable stacking fault energy for a given lattice constant. Currently allowed values are:

Returns

[unstable_stacking_fault_energy] : array containing one float

The relaxed unstable stacking fault energy of the monoatomic FCC crystal in the requested units.

get_unstable_twinning_fault_relaxed_energy_fcc

 get_unstable_twinning_fault_relaxed_energy_fcc(model, species, units, pressure=[0.0],
     pressure_units=['MPa'], pressure_tol=[0.1], method=['relaxation'])

Retrieve the relaxed unstable twinning fault energy (UTFE) of a face-centered monoatomic cubic crystal at zero temperature and a specified pressure. The UTFE corresponds to the energy barrier for rigidly slipping one part of an infinite crystal on a {111} plane adjacent to a preexisting intrinsic stacking fault relative to the other part along a <112> direction (fcc partial dislocation direction). Relaxation of the atomic coordinates is performed perpendicular to the fault plane.

KIM Property Definition: unstable-twinning-fault-relaxed-energy-fcc-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query Etwin_unstable get_unstable_twinning_fault_relaxed_energy_fcc species=["Al"] units=["eV/angstrom^2"]

python:

  from kim_query import get_unstable_twinning_fault_relaxed_energy_fcc
  get_unstable_twinning_fault_relaxed_energy_fcc(["MO_123629422045_005"], ["Al"], ["eV/angstrom^2"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["eV/angstrom^2"]'       \
       https://query.openkim.org/api/get_unstable_twinning_fault_relaxed_energy_fcc

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

species : array containing one string

The standard chemical symbol of the single atomic species comprising the crystal, e.g. "Al".

units : array containing one double-quoted string

A physical unit of energy per unit area supported by GNU units in which the relaxed intrinsic stacking fault energy will be returned, e.g. "eV/angstrom^2".

pressure : array containing one float, optional

The pressure at which the relaxed unstable twinning fault energy is to be computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to relax the atomic positions in order to compute the unstable twinning fault energy for a given lattice constant. Currently allowed values are:

Returns

[unstable_twinning_fault_energy] : array containing one float

The relaxed unstable twinning fault energy of the monoatomic FCC crystal in the requested units.

get_surface_energy_ideal_cubic

 get_surface_energy_ideal_cubic(model, crystal, species, miller, units, method=['TD_955413365818'])

Retrieve ideal surface energy of a high-symmetry surface in a cubic crystal comprised of one or more species at zero temperature and pressure, as computed by the latest current version of the SurfaceEnergyCubicCrystalBrokenBondFit Test Driver (TD_955413365818).

KIM Property Definition: surface-energy-ideal-cubic-crystal

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query Eideal get_surface_energy_ideal_cubic crystal=["fcc"] miller=[1,0,0] species=["Al"] units=["eV/angstrom^2"]

python:

  from kim_query import get_surface_energy_ideal_cubic
  get_surface_energy_ideal_cubic(["MO_123629422045_005"], ["fcc"], ["Al"], [1,0,0], ["eV/angstrom^2"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["eV/angstrom^2"]'       \
       https://query.openkim.org/api/get_surface_energy_ideal_cubic

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the cubic crystal. Currently allowed values are "bcc", "diamond", "fcc", and "sc".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

miller : array of three integers

The miller indices of the surface. Currently allowed values are [1,0,0], [1,1,0], [1,1,1], [1,2,1].

units : array containing one double-quoted string

A physical unit of energy per unit area supported by GNU units in which the relaxed intrinsic stacking fault energy will be returned, e.g. "eV/angstrom^2".

method : array containing one double-quoted string, optional

The Test Driver used to compute the ideal surface energy for a given lattice constant. Currently allowed values are:

Returns

[ideal_surface_energy] : array containing one float

The ideal surface energy in the requested units.

get_surface_energy_relaxed_cubic

 get_surface_energy_relaxed_cubic(model, crystal, species, miller, units, temperature=[0.0],
     temperature_units=['K'], temperature_tol=[0.1], pressure=[0.0], pressure_units=['MPa'],
     pressure_tol=[0.1], method=['fire'])

Retrieve free energy of a cubic relaxed surface energy of a high-symmetry surface in a cubic crystal comprised of one or more species at a given temperature and hydrostatic pressure. This corresponds to the 'relaxed' surface energy found by performing an energy minimization. At zero temperature, this corresponds to the potential energy rather than the free energy.

KIM Property Definition: surface-energy-cubic-crystal-npt

Usage Examples

LAMMPS:

  kim init EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005 metal
  kim query Erelaxed get_surface_energy_relaxed_cubic crystal=["fcc"] miller=[1,0,0] species=["Al"] units=["eV/angstrom^2"]

python:

  from kim_query import get_surface_energy_relaxed_cubic
  get_surface_energy_relaxed_cubic(["MO_123629422045_005"], ["fcc"], ["Al"], [1,0,0], ["eV/angstrom^2"])

curl:

  curl --data-urlencode 'model=["MO_123629422045_005"]' \
       --data-urlencode 'species=["Al"]'                \
       --data-urlencode 'units=["eV/angstrom^2"]'       \
       https://query.openkim.org/api/get_surface_relaxed_ideal_cubic

Parameters

model : array containing one double-quoted string

The KIM ID of the model used to compute the result

crystal : array containing one double-quoted string

The short name of the cubic crystal. Currently allowed values are "bcc", "diamond", "fcc", and "sc".

species : array of double-quoted strings

The standard chemical symbol(s) of the atomic species comprising the crystal, e.g. "Al".

miller : array of three integers

The miller indices of the surface. Currently allowed values are [1,0,0], [1,1,0], [1,1,1], [1,2,1].

units : array containing one double-quoted string

A physical unit of energy per unit area supported by GNU units in which the relaxed intrinsic stacking fault energy will be returned, e.g. "eV/angstrom^2".

temperature : array containing one float, optional

The temperature at which the surface energy is computed. This value should be given in the units specified by the 'temperature_units' argument. (Default: 0.0)

temperature_units : array containing one double-quoted string, optional

A physical unit of temperature supported by GNU units in which the 'temperature' argument is given. (Default: K)

temperature_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the temperature specified in the given temperature units. For example, if temperature_tol=0.1, temperature=293.15, temperature_units="K", then results retrieved by the query must be computed at a temperature of 293.15 +/- 0.1 K. If multiple matching results are found, an error is returned. (Default: 0.1)

pressure : array containing one float, optional

The pressure at which the surface energy is computed. This value should be given in the units specified by the 'pressure_units' argument. (Default: 0.0)

pressure_units : array containing one double-quoted string, optional

A physical unit of pressure supported by GNU units in which the 'pressure' argument is given. (Default: MPa)

pressure_tol : array containing one float, optional

Indicates a tolerance within which the query results must match the pressure specified in the given pressure units. For example, if pressure_tol=0.1, pressure=0.101325, pressure_units="MPa", then results retrieved by the query must be computed at a pressure of 0.101325 +/- 0.1 MPa. If multiple matching results are found, an error is returned. (Default: 0.1)

method : array containing one double-quoted string, optional

The algorithm used to minimize the surface energy with respect to the atomic positions. Currently allowed values are:

Returns

[relaxed_surface_energy] : array containing one float

The relaxed surface energy in the requested units.