AFLOW Database Entries

Once an initial search has been performed using aflow, the results are setup as a python generator that returns Entry objects. These provide immediate access to properties specified in the search query, and lazy access to all other properties that are available for the given material entry.

Provides class and methods for abstracting the data from AFLOW into python.

class aflow.entries.AflowFile(aurl, filename)

Represents a single file for an entry in AFLOW and allows easy access to download it.

Parameters:

• aurl (str) – URL for the entry in AFLOW.
• filename (str) – name of the file.

class aflow.entries.AflowFiles(entry)

Represents a collection of files for an entry in AFLOW and allows easy access to download them.

Parameters:entry (Entry) – database entry object that has a list of the files and remote URL for accessing them.

class aflow.entries.Entry(**kwargs)

Encapsulates the result of a single material entry in the AFLOW database.

Note

Additional keyword values will be loaded lazily as requested (using additional HTTP requests). For optimization, it is recommended to request all known keywords up front.

Parameters:kwargs (dict) – of key-value pairs obtained from the initial AFLUX request.

attributes

dict – of key-value pairs requested for the given material. This will only be identical to the passed in the keyword arguments if no additional property requests have been made.

raw

dict – original response dictionary (without any cast values).

Bravais_lattice_orig

original bravais lattice (optional). Units – ``.

Returns:Returns the Bravais lattice of the original unrelaxed structure before the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

Bravais_lattice_orig=MCLC

Bravais_lattice_relax

relaxed bravais lattice (optional). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• stress_tensor()

Returns:Returns the Bravais lattice of the original relaxed structure after the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

Bravais_lattice_relax=MCLC

Egap

electronic energy band gap (mandatory). Units – eV.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Band gap calculated with the approximations and pseudopotentials described by other keywords. Return type:float

Examples

You can expect the content of the result to be something like:

Egap=2.5

Egap_fit

fitted band gap (mandatory). Units – eV.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Simple cross-validated correction (fit) of Egap. Return type:float

Examples

You can expect the content of the result to be something like:

Egap_fit=3.5

Egap_type

band gap type (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Given a band gap, this keyword describes if the system is a metal, a semi-metal, an insulator with direct or indirect band gap. Return type:str

Examples

You can expect the content of the result to be something like:

Egap_type=insulator_direct

PV_atom

atomic pressure*volume (mandatory). Units – eV/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Pressure multiplied by volume of the atom. Return type:float

Examples

You can expect the content of the result to be something like:

PV_atom=12.13

PV_cell

unit cell pressure*volume (mandatory). Units – eV.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Pressure multiplied by volume of the unit cell. Return type:float

Examples

You can expect the content of the result to be something like:

PV_cell=12.13

Pearson_symbol_orig

original Pearson symbol (mandatory). Units – ``.

Returns:Returns the Pearson symbol of the original-unrelaxed structure before the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

Pearson_symbol_orig=mS32

Pearson_symbol_relax

relaxed Pearson symbol (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• stress_tensor()

Returns:Returns the Pearson symbol of the relaxed structure after the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

Pearson_symbol_relax=mS32

Pulay_stress

Pulay Stress (mandatory). Units – kbar.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns a metric of the basis set inconsistency for the calculation. Return type:float

Examples

You can expect the content of the result to be something like:

pulay_stress=10.0

Pullay_stress

Pulay Stress (mandatory). Units – kbar.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns a metric of the basis set inconsistency for the calculation. Return type:float

Examples

You can expect the content of the result to be something like:

Pullay_stress=10.0

ael_bulk_modulus_reuss

AEL Reuss bulk modulus (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the bulk modulus as calculated using the Reuss method with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_bulk_modulus_reuss=105.315

ael_bulk_modulus_voigt

AEL Voigt bulk modulus (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the bulk modulus as calculated using the Voigt method with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_bulk_modulus_voiht=105.315

ael_bulk_modulus_vrh

AEL VRH bulk modulus (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the bulk modulus as calculated using the Voigt-Reuss-Hill average with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_bulk_modulus_vrh=105.315

ael_elastic_anistropy

AEL elastic anistropy (optional). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the elastic anistropy as calculated with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_elastic_anistropy=0.0008165

ael_poisson_ratio

AEL Poisson ratio (optional). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the istropic Poisson ratio as calculated with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_poisson_ratio=0.216

ael_shear_modulus_reuss

AEL Reuss shear modulus (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the shear modulus as calculated using the Reuss method with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_shear_modulus_reuss=73.787

ael_shear_modulus_voigt

AEL Voigt shear modulus (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the shear modulus as calculated using the Voigt method with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_shear_modulus_voigt=73.799

ael_shear_modulus_vrh

AEL VRH shear modulus (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the shear modulus as calculated using the Voigt-Reuss-Hill average with AEL. Return type:float

Examples

You can expect the content of the result to be something like:

ael_shear_modulus_vrh=73.793

aflow_version

aflow version (optional). Units – ``.

Returns:Returns the version number of AFLOW used to perform the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

aflow_version=aflow30641

aflowlib_date

material generation date (optional). Units – ``.

Returns:Returns the date of the AFLOW post-processor which generated the entry for the library. Return type:str

Examples

You can expect the content of the result to be something like:

aflowlib_date=20140204_13:10:39_GMT-5

aflowlib_entries

aflowlib entries (conditional). Units – ``.

Returns:For projects and set-layer entries, aflowlib_entries lists the available sub-entries which are associated with the $aurl of the subdirectories. By parsing $aurl/?aflowlib_entries (containing $aurl/aflowlib_entries_number entries) the user finds further locations to interrogate. Return type:list

Examples

You can expect the content of the result to be something like:

aflowlib_entries=AgAl,AgAs,AgAu,AgB_h,AgBa_sv,AgBe_sv,AgBi_d,AgBr,AgCa_sv,...

aflowlib_entries_number

aflowlib entry count (conditional). Units – ``.

Returns:For projects and set-layer entries, aflowlib_entrieslists the available sub-entries which are associated with the $aurl of the subdirectories. By parsing $aurl/?aflowlib_entries (containing $aurl/aflowlib_entries_number entries) the user finds further locations to interrogate. Return type:float

Examples

You can expect the content of the result to be something like:

aflowlib_entries_number=654

aflowlib_version

aflowlib version (optional). Units – ``.

Returns:Returns the version of the AFLOW post-processor which generated the entry for the library. Return type:str

Examples

You can expect the content of the result to be something like:

aflowlib_version=3.1.103

agl_acoustic_debye

AGL acoustic Debye temperature (optional). Units – K.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the acoustic Debye temperature as calculated with AGL. Return type:float

Examples

You can expect the content of the result to be something like:

agl_acoustic_debye=492

agl_bulk_modulus_isothermal_300K

AGL isothermal bulk modulus 300K (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the isothermal bulk modulus at 300K as calculated with AGL. Return type:float

Examples

You can expect the content of the result to be something like:

agl_bulk_modulus_isothermal_300K=96.6

agl_bulk_modulus_static_300K

AGL static bulk modulus 300K (optional). Units – GPa.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the static bulk modulus at 300K as calculated with AGL. Return type:float

Examples

You can expect the content of the result to be something like:

agl_bulk_modulus_static_300K=99.6

agl_debye

AGL Debye temperature (optional). Units – K.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the Debye temperature as calculated with AGL. Return type:float

Examples

You can expect the content of the result to be something like:

agl_debye=620

agl_gruneisen

AGL Gruneisen parameter (optional). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the Gruneisen parameter as calculated with AGL. Return type:float

Examples

You can expect the content of the result to be something like:

agl_gruneisen=2.06

agl_heat_capacity_Cp_300K

AGL heat capacity Cp (optional). Units – kB/cell.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the heat capacity at constant pressure as calculated with AGL at 300K. Return type:float

Examples

You can expect the content of the result to be something like:

agl_heat_capacity_Cp_300K=5.502

agl_heat_capacity_Cv_300K

AGL heat capacity Cv (optional). Units – kB/cell.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the heat capacity at constant volume as calculated with AGL at 300K. Return type:float

Examples

You can expect the content of the result to be something like:

agl_heat_capacity_Cv_300K=4.901

agl_thermal_conductivity_300K

AGL thermal conductivity (optional). Units – W/m*K.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the thermal conductivity as calculated with AGL at 300K. Return type:float

Examples

You can expect the content of the result to be something like:

agl_thermal_conductivity_300K=24.41

agl_thermal_expansion_300K

AGL thermal expansion (optional). Units – 1/K.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the thermal expansion as calculated with AGL at 300K. Return type:float

Examples

You can expect the content of the result to be something like:

agl_thermal_expansion_300K=4.997e-05

atoms(pattern='CONTCAR.relax*', quippy=False, keywords=None, calculator=None)

Creates a ase.atoms.Atoms or a quippy.atoms.Atoms object for this database entry.

Parameters:

• pattern (str) – pattern for choosing the file to generate the atomic lattice and positions from. The pattern is passed to fnmatch() and the last entry in the list is returned (so that CONTCAR.relax2 would be returned preferentially over CONTCAR.relax1 or CONTCAR.relax).
• quippy (bool) – when True, return a quippy.atoms.Atoms object.
• keywords (dict) – keys are keyword obects accessible from aflow.K; values are desired str names in the parameters dictionary of the atoms object.
• calculator (ase.calculators.Calculator) – calculator to set for the newly created atoms object.

Examples

Generate a quippy.atoms.Atoms object and include the total energy and forces. Assume that result is a valid aflow.search() object.

>>> entry = result[0] #Get the first result in the set.
>>> keywords = {K.energy_cell: "dft_energy", K.forces: "dft_force"}
>>> entry.atoms(quippy=True, keywords=keywords)

auid

AFLOWLIB Unique Identifier (mandatory). Units – ``.

Returns:AFLOWLIB Unique Identifier for the entry, AUID, which can be used as a publishable object identifier. Return type:str

Examples

You can expect the content of the result to be something like:

auid=aflow:e9c6d914c4b8d9ca

aurl

AFLOWLIB Uniform Resource Locator (mandatory). Units – ``.

Returns:AFLOWLIB Uniform Resource Locator returns the AURL of the entry. Return type:str

Examples

You can expect the content of the result to be something like:

aurl=aflowlib.duke.edu:AFLOWDATA/LIB3_RAW/Bi_dRh_pvTi_sv/T0003.ABC:LDAU2

author

author (optional). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns the name (not necessarily an individual) and affiliation associated with authorship of the data. Return type:list

Examples

You can expect the content of the result to be something like:

author=Marco_Buongiorno_Nardelli,Ohad_Levy,Jesus_Carrete

bader_atomic_volumes

atomic volume per atom (optional). Units – ų.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the volume of each atom of the primitive cell as calculated by the Bader Atoms in Molecules Analysis. This volume encapsulates the electron density associated with each atom above a threshold of 0.0001 electrons. Return type:list

Examples

You can expect the content of the result to be something like:

bader_atomic_volumes=15.235,12.581,13.009

bader_net_charges

partial charge per atom (optional). Units – electrons.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns a comma delimited set of partial charges per atom of the primitive cell as calculated by the Bader Atoms in Molecules Analysis. Return type:list

Examples

You can expect the content of the result to be something like:

bader_net_charges=0.125,0.125,-0.25

calculation_cores

used CPU cores (optional). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Number of processors/cores used for the calculation. Return type:float

Examples

You can expect the content of the result to be something like:

calculation_cores=32

calculation_memory

used RAM (optional). Units – Megabytes.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:The maximum memory used for the calculation. Return type:float

Examples

You can expect the content of the result to be something like:

calculation_memory=32

calculation_time

used time (optional). Units – seconds.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Total time taken for the calculation. Return type:float

Examples

You can expect the content of the result to be something like:

calculation_time=32

catalog

catalog (optional). Units – ``.

Returns:Returns the context set for the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

catalog=icsd

code

ab initio code (optional). Units – ``.

Returns:Returns the software name and version used to perform the simulation. Return type:str

Examples

You can expect the content of the result to be something like:

code=vasp.4.6.35

composition

composition (optional). Units – ``.

Returns:Returns a comma delimited composition description of the structure entry in the calculated cell. Return type:list

Examples

You can expect the content of the result to be something like:

composition=2,6,6

compound

chemical formula (mandatory). Units – ``.

Returns:Returns the composition description of the compound in the calculated cell. Return type:str

Examples

You can expect the content of the result to be something like:

compound=Co2Er6Si6

corresponding

coresponding (optional). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns the name (not necessarily an individual) and affiliation associated with the data origin concerning correspondence about data. Return type:list

Examples

You can expect the content of the result to be something like:

corresponding=M_Buongiorno_Nardelli_mbn@unt.edu

data_api

REST API version (mandatory). Units – ``.

Returns:AFLOWLIB version of the entry, API.} Return type:str

Examples

You can expect the content of the result to be something like:

data_api=aapi1.0

data_language

data language (optional). Units – ``.

Returns:Gives the language of the data in AFLOWLIB. Return type:list

Examples

You can expect the content of the result to be something like:

data_language=aflowlib

data_source

data source (optional). Units – ``.

Returns:Gives the source of the data in AFLOWLIB. Return type:list

Examples

You can expect the content of the result to be something like:

data_source=aflowlib

delta_electronic_energy_convergence

Electronic Energy of Convergence Step (optional). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns the change in energy from the last step of the convergence iteration. Return type:float

Examples

You can expect the content of the result to be something like:

delta_electronic_energy_convergence=6.09588e-05

delta_electronic_energy_threshold

Electronic Energy of Convergence Threshold (optional). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns the maximimum change in energy required for the convergence iteration. Return type:float

Examples

You can expect the content of the result to be something like:

delta_electronic_energy_threshold=0.0001

density

mass density (optional). Units – grams/cm³.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns the mass density in grams/cm3. Return type:float

Examples

You can expect the content of the result to be something like:

density=7.76665

dft_type

DFT type (optional). Units – ``.

Returns:Returns information about the pseudopotential type, the exchange correlation functional used (normal or hybrid) and use of GW. Return type:list

Examples

You can expect the content of the result to be something like:

dft_type=PAW_PBE,HSE06

eentropy_atom

atomistic electronic entropy (optional). Units – eV/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the electronic entropy of the atom used to converge the ab initio calculation (smearing). Return type:float

Examples

You can expect the content of the result to be something like:

eentropy_atom=0.0011

eentropy_cell

unit cell electronic entropy (optional). Units – eV/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the electronic entropy of the unit cell used to converge the ab initio calculation (smearing). Return type:float

Examples

You can expect the content of the result to be something like:

eentropy_cell=0.0011

energy_atom

atomic energy (mandatory). Units – eV/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns the total ab initio energy per atom- the value of energy_cell/$N$). Return type:float

Examples

You can expect the content of the result to be something like:

energy_atom=-82.1656

energy_cell

unit cell energy (mandatory). Units – eV.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns the total ab initio energy of the unit cell, E. At T=0K and p=0, this is the internal energy of the system (per unit cell). Return type:float

Examples

You can expect the content of the result to be something like:

energy_cell=-82.1656

energy_cutoff

energy cutoff (optional). Units – eV.

Returns:Set of energy cut-offs used during the various steps of the calculations. Return type:list

Examples

You can expect the content of the result to be something like:

energy_cutoff=384.1,384.1,384.1

enthalpy_atom

atomic enthalpy (mandatory). Units – eV/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns the enthalpy per atom- the value of enthalpy_cell/N). Return type:float

Examples

You can expect the content of the result to be something like:

enthalpy_atom=-82.1656

enthalpy_cell

unit cell enthalpy (mandatory). Units – eV.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns the enthalpy of the system of the unit cell, H = E + PV. Return type:float

Examples

You can expect the content of the result to be something like:

enthalpy_cell=-82.1656

enthalpy_formation_atom

atomic formation enthalpy (mandatory). Units – eV/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the formation enthalpy DeltaHFatomic per atom). Return type:float

Examples

You can expect the content of the result to be something like:

enthalpy_formation_atom=-33.1587

enthalpy_formation_cell

unit cell formation enthalpy (mandatory). Units – eV.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the formation enthalpy DeltaHF per unit cell. Return type:float

Examples

You can expect the content of the result to be something like:

enthalpy_formation_cell=-33.1587

entropic_temperature

entropic temperature (mandatory). Units – Kelvin.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the entropic temperature for the structure. Return type:float

Examples

You can expect the content of the result to be something like:

entropic_temperature=1072.1

forces

Quantum Forces (optional). Units – eV/Å.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Final quantum mechanical forces (Fi,Fj,Fk) in the notation of the code. Return type:numpy.ndarray

Examples

You can expect the content of the result to be something like:

forces=0,-0.023928,0.000197;0,0.023928,-0.000197;...

geometry

unit cell basis (mandatory). Units – Å.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns geometrical data describing the unit cell in the usual a,b,c,alpha,beta,gamma notation. Return type:list

Examples

You can expect the content of the result to be something like:

geometry=18.82,18.82,18.82,32.41,32.41,32.41

keywords

Title (mandatory). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:This includes the list of keywords available in the entry, separated by commas. Return type:list

Examples

You can expect the content of the result to be something like:

keywords=aurl,auid,loop,code,compound,prototype,nspecies,natoms,...

kpoints

K-point mesh (optional). Units – ``.

Returns:Set of k-point meshes uniquely identifying the various steps of the calculations, e.g. relaxation, static and electronic band structure (specifying the k-space symmetry points of the structure). Return type:dict

Examples

You can expect the content of the result to be something like:

kpoints=10,10,10;16,16,16;G-X-W-K-G-L-U-W-L-K+U-X

lattice_system_orig

original lattice system (mandatory). Units – ``.

Returns:Return the lattice system and lattice variation (Brillouin zone) of the original-unrelaxed structure before the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

lattice_system_orig=rhombohedral

lattice_system_relax

relaxed lattice system (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• stress_tensor()

Returns:Return the lattice system and lattice variation (Brillouin zone) of the relaxed structure after the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

lattice_system_relax=rhombohedral

lattice_variation_orig

original lattice variation (mandatory). Units – ``.

Returns:Return the lattice system and lattice variation (Brillouin zone) of the original-unrelaxed structure before the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

lattice_variation_orig=rhombohedral

lattice_variation_relax

relaxed lattice variation (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• stress_tensor()

Returns:Return the lattice system and lattice variation (Brillouin zone) of the relaxed structure after the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

lattice_variation_relax=rhombohedral

ldau_TLUJ

on site coulomb interaction (mandatory). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:This vector of numbers contains the parameters of the DFT+U calculations, based on a corrective functional inspired by the Hubbard model. Return type:list

Examples

You can expect the content of the result to be something like:

ldau_TLUJ=2;2,0,0;5,0,0;0,0,0

loop

process category (optional). Units – ``.

Returns:Informs the user of the type of post-processing that was performed. Return type:list

Examples

You can expect the content of the result to be something like:

loop=thermodynamics,bands,magnetic

natoms

number of atoms in unit cell (mandatory). Units – ``.

Returns:Returns the number of atoms in the unit cell of the structure entry. The number can be non integer if partial occupation is considered within appropriate approximations. Return type:float

Examples

You can expect the content of the result to be something like:

natoms=12

nbondxx

nearest neighbor bond lengths (optional). Units – Å.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Nearest neighbors bond lengths of the relaxed structure per ordered set of species Ai,Aj greater than or equal to i. Return type:list

Examples

You can expect the content of the result to be something like:

nbondxx=1.2599,1.0911,1.0911,1.7818,1.2599,1.7818

node_CPU_Cores

available CPU cores (optional). Units – ``.

Returns:Information about the number of cores in the node/cluster where the calculation was performed. Return type:float

Examples

You can expect the content of the result to be something like:

node_CPU_Cores=12

node_CPU_MHz

CPU rate (optional). Units – Megahertz.

Returns:Information about the CPU speed in the node/cluster where the calculation was performed. Return type:float

Examples

You can expect the content of the result to be something like:

node_CPU_MHz=12

node_CPU_Model

CPU model (optional). Units – ``.

Returns:Information about the CPU model in the node/cluster where the calculation was performed. Return type:str

Examples

You can expect the content of the result to be something like:

node_CPU_Model=12

node_RAM_GB

available RAM (optional). Units – Gigabytes.

Returns:Information about the RAM in the node/cluster where the calculation was performed. Return type:float

Examples

You can expect the content of the result to be something like:

node_RAM_GB=12

nspecies

species count (mandatory). Units – ``.

Returns:Returns the number of species in the system (e.g., binary = 2, ternary = 3, etc.). Return type:float

Examples

You can expect the content of the result to be something like:

nspecies=3

positions_cartesian

relaxed absolute positions (mandatory). Units – Å.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Final Cartesian positions (xi,xj,xk) in the notation of the code. Return type:numpy.ndarray

Examples

You can expect the content of the result to be something like:

positions_cartesian=0,0,0;18.18438,0,2.85027;...

positions_fractional

relaxed relative positions (mandatory). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Final fractional positions (xi,xj,xk) with respect to the unit cell as specified in $geometry. Return type:numpy.ndarray

Examples

You can expect the content of the result to be something like:

positions_fractional=0,0,0;0.25,0.25,0.25;...

pressure

external pressure (mandatory). Units – kbar.

Returns:Returns the target pressure selected for the simulation. Return type:float

Examples

You can expect the content of the result to be something like:

pressure=10.0

pressure_final

resulting pressure (mandatory). Units – kbar.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns the external pressure achieved by the simulation. Return type:float

Examples

You can expect the content of the result to be something like:

pressure_final=10.0

pressure_residual

residual pressure (mandatory). Units – kbar.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns the external pressure achieved by the simulation. Return type:float

Examples

You can expect the content of the result to be something like:

pressure_residual=10.0

prototype

original prototype (mandatory). Units – ``.

Returns:Returns the AFLOW unrelaxed prototype which was used for the calculation. Return type:str

Examples

You can expect the content of the result to be something like:

prototype=T0001.A2BC

scintillation_attenuation_length

attenuation length (mandatory). Units – cm.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns the scintillation attenuation length of the compound in cm. Return type:float

Examples

You can expect the content of the result to be something like:

scintillation_attenuation_length=2.21895

sg

space group of compound (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• stress_tensor()

Returns:Evolution of the space group of the compound. The first, second and third string represent space group name/number before the first, after the first, and after the last relaxation of the calculation. Return type:list

Examples

You can expect the content of the result to be something like:

sg=Fm-3m#225,Fm-3m#225,Fm-3m#225

sg2

refined space group of compound (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• stress_tensor()

Returns:Evolution of the space group of the compound. The first, second and third string represent space group name/number before the first, after the first, and after the last relaxation of the calculation. Return type:list

Examples

You can expect the content of the result to be something like:

sg2=Fm-3m#225,Fm-3m#225,Fm-3m#225

spacegroup_orig

original space group number (mandatory). Units – ``.

Returns:Returns the spacegroup number of the original-unrelaxed structure before the calculation. Return type:float

Examples

You can expect the content of the result to be something like:

spacegroup_orig=225

spacegroup_relax

relaxed space group number (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• stress_tensor()

Returns:Returns the spacegroup number of the relaxed structure after the calculation. Return type:float

Examples

You can expect the content of the result to be something like:

spacegroup_relax=225

species

atomic species (mandatory). Units – ``.

Returns:Species of the atoms in this material. Return type:list

Examples

You can expect the content of the result to be something like:

species=Y,Zn,Zr

species_pp

pseudopotential of chemical speciess (mandatory). Units – ``.

Returns:Pseudopotentials of the atomic species. Return type:list

Examples

You can expect the content of the result to be something like:

species_pp=Y,Zn,Zr

species_pp_ZVAL

valence atoms per species (optional). Units – electrons.

Returns:Returns the number of valence electrons of the atomic species. Return type:list

Examples

You can expect the content of the result to be something like:

species_pp_ZVAL=3

species_pp_version

pseudopotential version and species (mandatory). Units – ``.

Returns:Species of the atoms, pseudopotentials species, and pseudopotential versions. Return type:list

Examples

You can expect the content of the result to be something like:

species_pp_version=Y,Zn,Zr

spinD

spin decomposition over unit cell (mandatory). Units – μ_B.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:For spin polarized calculations, the spin decomposition over the atoms of the cell. Return type:list

Examples

You can expect the content of the result to be something like:

spinD=0.236,0.236,-0.023,1.005

spinF

magnetization of unit cell at Fermi level (mandatory). Units – μ_B.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:For spin polarized calculations, the magnetization of the cell at the Fermi level. Return type:float

Examples

You can expect the content of the result to be something like:

spinF=0.410879

spin_atom

atomic spin polarization (mandatory). Units – μ_B/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:For spin polarized calculations, the magnetization per atom. Return type:float

Examples

You can expect the content of the result to be something like:

spin_atom=2.16419

spin_cell

unit cell spin polarization (mandatory). Units – μ_B.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:For spin polarized calculations, the total magnetization of the cell. Return type:float

Examples

You can expect the content of the result to be something like:

spin_cell=2.16419

sponsor

sponsor (optional). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns information about funding agencies and other sponsors for the data. Return type:list

Examples

You can expect the content of the result to be something like:

sponsor=DOD_N000141310635,NIST_70NANB12H163

stoich

unit cell stoichiometry (optional). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Similar to composition, returns a comma delimited stoichiometry description of the structure entry in the calculated cell. Return type:list

Examples

You can expect the content of the result to be something like:

stoichiometry=0.5,0.25,0.25

stoichiometry

unit cell stoichiometry (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Similar to composition, returns a comma delimited stoichiometry description of the structure entry in the calculated cell. Return type:list

Examples

You can expect the content of the result to be something like:

stoichiometry=0.5,0.25,0.25

stress_tensor

Stress Tensor (mandatory). Units – ``.

Warning

This keyword is still listed as development level. Use it knowing that it is subject to change or removal.

Returns:Returns the stress tensor of the completed calculation. Return type:list

Examples

You can expect the content of the result to be something like:

stress_tensor=-0.96,-0,-0,-0,-0.96,-0,-0,-0,-0.96

valence_cell_iupac

unit cell IUPAC valence (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns IUPAC valence, the maximum number of univalent atoms that may combine with the atoms. Return type:float

Examples

You can expect the content of the result to be something like:

valence_cell_iupac=22

valence_cell_std

unit cell standard valence (mandatory). Units – ``.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• kpoints()

Returns:Returns standard valence, the maximum number of univalent atoms that may combine with the atoms. Return type:float

Examples

You can expect the content of the result to be something like:

valence_cell_std=22

volume_atom

atomic volume (mandatory). Units – ų/atom.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns the volume per atom in the unit cell. Return type:float

Examples

You can expect the content of the result to be something like:

volume_atom=100.984

volume_cell

unit cell volume (mandatory). Units – ų.

Note

The following verifications are available for this keyword. They are exposed as additional methods on this object.

• energy_cutoff()
• forces()
• kpoints()
• pressure_residual()
• stress_tensor()

Returns:Returns the volume of the unit cell. Return type:float

Examples

You can expect the content of the result to be something like:

volume_cell=100.984