Input File Description

Here we provide a description of the input variables related to each of the applications in the code. Phoebe tries to check the variables provided in input, and stops the code if it detects missing or invalid input parameters.

Note that the executable, phoebe is the same for all applications. The applications are selected through the appName parameter.

Note

The input file text is case sensitive!

QE to Phoebe

Functionality: Convert the electron-phonon coupling from Quantum-ESPRESSO format to Phoebe format. This postprocesses the data for Wannier interpolation or EPA calculations in Phoebe.

Input variables

appName = “elPhQeToPhoebe”

phFC2FileName
elPhInterpolation
electronH0Name
wannier90Prefix
quantumEspressoPrefix
epaMinEnergy
epaMaxEnergy
epaNumBins
epaSmearingEnergy
distributedElPhCoupling

Sample input file (Wannier interpolation)

appName = "elPhQeToPhoebe"
elPhInterpolation = "wannier"

phFC2FileName = "./silicon.fc"
electronH0Name = "./si_tb.dat",
wannier90Prefix = "si"
quantumEspressoPrefix = "silicon"

Sample input file (EPA)

appName = "elPhQeToPhoebe"
elPhInterpolation = "epa"

phFC2FileName = "./silicon.fc"
electronH0Name = "./out/silicon.xml",
quantumEspressoPrefix = "silicon"

electronFourierCutoff = 4.
epaMinEnergy = -4. eV
epaMaxEnergy = 10. eV
epaNumBins = 10
epaSmearingEnergy = 0.05 eV

Phonon BTE Solver

Functionality: Build and solve the phonon Boltzmann Transport Equation (BTE) to compute phonon transport properties such as thermal conductivity, relaxation times and viscosity.

Input variables

appName = “phononTransport”

Sample input file

appName = "phononTransport"
phFC2FileName = "./ForceConstants2nd"
sumRuleFC2 = "crystal"
phFC3FileName = "./ForceConstants3rd"
qMesh = [10,10,10]
temperatures = [300.]
smearingMethod = "adaptiveGaussian"
solverBTE = ["variational","relaxons"]
scatteringMatrixInMemory = true
boundaryLength = 10. mum

Electron BTE Solver

Functionality: Build and solve the electronic Boltzmann Transport Equation (BTE) using Wannier interpolation. Output quantites are electrical conductivity, electronic thermal conductivity, Seebeck coefficient, electron viscosity, and electronic lifetimes (on the kMesh used in this calculation).

Input variables

appName = “electronWannierTransport”

Sample input file

appName = "electronWannierTransport"
phFC2FileName = "./silicon.fc"
sumRuleFC2 = "crystal"
electronH0Name = "./si_tb.dat",
elphFileName = "silicon.phoebe.elph.dat"
kMesh = [15,15,15]
temperatures = [300.]
dopings = [1.e21]
smearingMethod = "gaussian"
smearingWidth = 0.5 eV
windowType = "population"

EPA Transport

Functionality: Build and solve the electronic Boltzmann Transport Equation (BTE) using Wannier interpolation. Output quantites are electrical conductivity, electronic thermal conductivity, Seebeck coefficient, electron viscosity, and electronic lifetimes as a function of bin energy.

Input variables

appName = “transportEPA”

electronH0Name
epaFileName
electronFourierCutoff
epaEnergyStep
epaEnergyRange
kMesh
temperatures
dopings

Sample input file

appName = "transportEpa"

electronH0Name = "./out/silicon.xml",
epaFileName = "./silicon.phoebe.epa.dat"

electronFourierCutoff = 4.
epaEnergyStep = 0.01 eV
epaEnergyRange = 3.0 eV

kMesh = [10,10,10]
temperatures = [300.]
dopings = [1.0e21]

Phonon Lifetimes on a Path

Functionality: Compute phonon lifetimes/linewidths on a specified path through the Brillouin zone.

Input variables

appName = “phononLifetimes”

phFC2FileName
sumRuleFC2
phFC3FileName
qMesh
temperatures
minTemperature
maxTemperature
deltaTemperature
smearingMethod
smearingWidth
constantRelaxationTime
withIsotopeScattering
masses
isotopeCouplings
boundaryLength
deltaPath
begin/end point path
phonopyDispFileName
dispFCFileName

Sample input file

appName = "phononLifetimes"
phFC2FileName = "../Silicon/espresso.ifc2",
sumRuleFC2 = "simple"
phFC3FileName = "../Silicon/ShengBTEForceConstants3rd"
qMesh = [15,15,15]
temperatures = [600.]
smearingMethod = "gaussian"
smearingWidth = 10. cmm1
deltaPath = 0.01
begin point path
 L 0.50000  0.50000 0.5000 G 0.00000  0.00000 0.0000
 G 0.00000  0.00000 0.0000 X 0.50000  0.00000 0.5000
 X 0.50000 -0.50000 0.0000 K 0.37500 -0.37500 0.0000
 K 0.37500 -0.37500 0.0000 G 0.00000  0.00000 0.0000
end point path

Electron Lifetimes on a Path

Functionality: Compute electron-phonon lifetimes/linewidths on a path through the Brillouin zone using Wannier interpolation.

Input variables

appName = “electronLifetimes”

Sample input file

appName = "electronLifetimes"
phFC2FileName = "./silicon.fc",
sumRuleFC2 = "crystal"
electronH0Name = "./si_tb.dat",
elphFileName = "./silicon.phoebe.elph.dat"
kMesh = [15,15,15]
temperatures = [600.]
dopings = [1.e22]
smearingMethod = "gaussian"
smearingWidth = 0.5 eV
deltaPath = 0.01
begin point path
 L 0.50000  0.50000 0.5000 G 0.00000  0.00000 0.0000
 G 0.00000  0.00000 0.0000 X 0.50000  0.00000 0.5000
 X 0.50000 -0.50000 0.0000 K 0.37500 -0.37500 0.0000
 K 0.37500 -0.37500 0.0000 G 0.00000  0.00000 0.0000
end point path

Phonon Dos

Functionality: Compute the phonon density of states.

Input variables

appName = “phononDos”

phFC2FileName
sumRuleFC2
qMesh
dosMinEnergy
dosMaxEnergy
dosDeltaEnergy
phonopyDispFileName
dispFCFileName
masses

Sample input file

phFC2FileName = "qespresso/silicon.fc",
sumRuleFC2 = "simple"
qMesh = [10,10,10]
appName = "phononDos"
dosMinEnergy = 0. cmm1
dosMaxEnergy = 600. cmm1
dosDeltaEnergy = 0.5 cmm1

Phonon Bands

Functionality: Compute the phonon band structure on a path through the Brillouin zone.

Input variables

appName = “phononBands”

phFC2FileName
sumRuleFC2
deltaPath
begin/end point path
phonopyDispFileName
dispFCFileName
masses

Sample input file (Quantum ESPRESSO)

appName = "phononBands"
sumRuleFC2 = "simple"

begin point path
 L 0.50000  0.50000 0.5000 G 0.00000  0.00000 0.0000
 G 0.00000  0.00000 0.0000 X 0.50000  0.00000 0.5000
 X 0.50000 -0.50000 0.0000 K 0.37500 -0.37500 0.0000
 K 0.37500 -0.37500 0.0000 G 0.00000  0.00000 0.0000
end point path

Sample input file (phono3py)

appName = "phononBands"
phFC2FileName = "fc2.hdf5"
dispFCFileName = "disp_fc3.yaml"
phonopyDispFileName = "phono3py_disp.yaml"
sumRuleFC2 = "simple"

begin point path
 G 0.000 0.000 0.000  X 0.000 0.500 0.500
 X 0.000 0.500 0.500  W 0.250 0.750 0.500
 W 0.250 0.750 0.500  L 0.500 0.500 0.500
 L 0.500 0.500 0.500  G 0.000 0.000 0.000
 G 0.000 0.000 0.000  K 0.375 0.750 0.375
end point path

Electron DoS

Electron DoS (Wannier interpolation)

Functionality: Compute the electronic density of states. Electronic bands are interpolated to a finer mesh using Wannier interpolation.

Input variables

appName = “electronWannierDos”

electronH0Name
fermiLevel
kMesh
dosMinEnergy
dosMaxEnergy
dosDeltaEnergy
begin/end crystal

Sample input file

electronH0Name = "qespresso/si_tb.dat",
kMesh = [10,10,10]
appName = "electronWannierDos"
dosMinEnergy = -6. eV
dosMaxEnergy = 20. eV
dosDeltaEnergy = 0.1 eV
begin crystal
 Si 0.00000   0.00000   0.00000
 Si 1.34940   1.34940   1.34940
end crystal

Electron DoS (Fourier interpolation)

Functionality: Compute the electronic density of states. Electronic bands are interpolated to a finer mesh using Fourier interpolation.

Input variables

appName = “electronFourierDos”

electronH0Name
kMesh
fermiLevel
dosMinEnergy
dosMaxEnergy
dosDeltaEnergy
electronFourierCutoff

Sample input file

electronH0Name = "qespresso/out/silicon.xml",
kMesh = [10,10,10]
appName = "electronFourierDos"
dosMinEnergy = -6. eV
dosMaxEnergy = 20. eV
dosDeltaEnergy = 0.1 eV
electronFourierCutoff = 4.

Electron Bands

Electron Bands (Wannier interpolation)

Functionality: Compute the phonon band structure on a path through the Brillouin zone. Electronic bands are interpolated to a finer mesh using Wannier interpolation.

Input variables

appName = “electronWannierBands”

electronH0Name
fermiLevel
deltaPath
begin/end point path
begin/end crystal

Sample input file

appName = "electronWannierBands"
electronH0Name = "qespresso/si_tb.dat",
deltaPath = 0.01
begin point path
 L 0.50000  0.50000 0.5000 G 0.00000  0.00000 0.0000
 G 0.00000  0.00000 0.0000 X 0.50000  0.00000 0.5000
 X 0.50000 -0.50000 0.0000 K 0.37500 -0.37500 0.0000
 K 0.37500 -0.37500 0.0000 G 0.00000  0.00000 0.0000
end point path
begin crystal
 Si 0.00000   0.00000   0.00000
 Si 1.34940   1.34940   1.34940
end crystal

Electron Bands (Fourier interpolation)

Functionality: Compute the electronic band structure on a path through the Brillouin zone. Electronic bands are interpolated to a finer mesh using Fourier interpolation.

Input variables

appName = “electronFourierBands”

electronH0Name
fermiLevel
deltaPath
electronFourierCutoff
begin/end point path

Sample input file

appName = "electronFourierBands"
electronH0Name = "qespresso/out/silicon.xml",
deltaPath = 0.01
electronFourierCutoff = 4.
begin point path
 L 0.50000  0.50000 0.5000 G 0.00000  0.00000 0.0000
 G 0.00000  0.00000 0.0000 X 0.50000  0.00000 0.5000
 X 0.50000 -0.50000 0.0000 K 0.37500 -0.37500 0.0000
 K 0.37500 -0.37500 0.0000 G 0.00000  0.00000 0.0000
end point path

Input Variable Descriptions

Below are descriptions of the input variables available in Phoebe, along with their formats and when applicable, default values. If no default value is listed, this means the default value is nothing. If a required variable is left blank, Phoebe will throw a related error message.

appName

Description: This parameter, which must always be present, identifies which app (functionality) you want to run.
Format: string
Required: yes

Possible values:

“elPhQeToPhoebe”: app to convert electron-phonon coupling from QE to Phoebe format (must be run before running any electron transport).
“phononTransport”: app to solve the phonon BTE and compute phonon transport properties.
“electronWannierTransport”: app to solve the electron BTE and compute electron transport properties.
“transportEPA”: app to solve the electron BTE and compute the electron transport properties using the EPA approximation.
“phononLifetimes”: app to compute the phonon lifetimes on a given Brillouin zone path.
“electronLifetimes”: app to compute the electron lifetimes on a given Brillouin zone path.
“phononDos”: app to compute the phonon density of states.
“phononBands”: app to compute the phonon bands on a Brillouin zone path.
“electronWannierDos”: app to compute the electron density of states with Wannier interpolation.
“electronFourierDos”: app to compute the electron density of states with Fourier interpolation.
“electronWannierBands”: app to compute the electron bands with Wannier interpolation on a Brillouin zone path.
“electronFourierBands”: app to compute the electron bands with Fourier interpolation on a Brillouin zone path.

phFC2FileName

Description: Path to a file containing harmonic force constants. File formats supported are: Quantum-ESPRESSO output of q2r.x (prefix.fc) or phono3py output (fc2.hdf5).
Format: string
Required: yes (for all phonon and electron-phonon apps)

phFC3FileName

Description: Path to a file containing anharmonic (3rd order) force constants. File formats supported are: ShengBTE (FORCE_CONSTANTS_3RD) or phono3py (fc3.hdf5).
Format: string
Required: yes (for phonon transport and lifetime apps)

phonopyDispFileName

Description: Path to the phono3py_disp.yaml file output by phono3py. (In the case of running only the harmonic phonons with phonopy, this file is named phonopy_disp.yaml).
Format: string
Required: yes (for calculations using phono3py)

dispFCFileName

Description: Path to the disp_fc3.yaml file output by phono3py. (In the case of running only the harmonic phonons with phonopy, this file is named disp.yaml.
Format: string
Required: yes (for calculations using phono3py)

sumRuleFC2

Description: If specified, applies an acoustic sum rule to the phonon harmonic force constants. Allowed values are “simple” or “crystal”, with the same algorithm and meaning of Quantum-ESPRESSO matdyn.x program.
Format: string
Required: yes (for phonon calculations)

qMesh

Description: Triplet of integers with the fine q-point Monkhorst-Pack mesh that will be used for Brillouin zone integrations of phonon properties.
Format: list of int
Required: yes (for phonon calculations)

kMesh

Description: Triplet of integers with the fine k-point Monkhorst-Pack mesh that will be used for Brillouin zone integrations of electronic properties. In electron-phonon transport calculations, qMesh is set to be equal to this value and does not need to be specified by the user.
Format: list of int
Required: yes (for electronic calculations)

temperatures

Description: List with the values of temperatures (in Kelvin) to be used in the calculation. If scatteringMatrixInMemory=true, only one value of temperature is allowed.
Format: list of doubles
Required: yes (for transport and lifetime calculations)

smearingMethod

Description: Selects the level of approximation for replacing the Dirac-delta approximating energy conservation. Allowed values are “gaussian” and “adaptiveGaussian” (preferred)
Format: string
Required: yes (for transport and lifetime calculations)

smearingWidth

Description: This parameter is required if smearingMethod = “gaussian”, where this parameter represents the full-width half-maximum of the Gaussian used to approximate the Dirac-delta conserving energy. Example: smearingWidth = 0.5 eV
Format: double+units
Required: yes (when smearingMethod = “gaussian”)

solverBTE

Description: If specified, solves the Boltzmann equation beyond the relaxation time approximation. Allowed values are: “variational”, “iterative”, and “relaxons”, see the Theory section for a detailed explanation. Example: solverBTE=[“variational”,”relaxons”]
Format: list of strings
Required: no

scatteringMatrixInMemory

Description: If true, the scattering matrix is kept in memory, and only one temperature is allowed. In exchange for a larger memory usage, exact BTE solvers are much faster. Disable this flag to reduce the memory footprint, at the cost of slowing down the exact BTE solvers.
Format: bool
Required: no
Default: true

symmetrizeMatrix

Description: If true, we enforce the symmetrix property of the scattering matrix A by doing A=(A^T+A)/2, where the transpose operation is made with respect to the wavevector indices. This operation increases the stability of the variational and relaxon solvers. Set this variable to false to increase the speed of the simulation in exchange for additional numerical noise.
Format: bool
Required: no
Default: true

distributedElPhCoupling

Description: If true, the electron-phonon coupling in the Wannier representation is distributed over MPI processes, helping reducing the memory requirements of a run. The MPI parallelization takes place over the number of irreducible q-points of the phonon calculation (which sets the upper number of MPI processes that can be used). If false, the electron-phonon coupling tensor is not distributed over MPI processes: calculations will be faster, but in exchange for a much larger memory requirement that can cause segmentation faults for some large use cases.
Format: bool
Required: no
Default: true

windowType

Description: Enables the window used to discard some phonon states that don’t contribute to transport. Possible values are “nothing”, “population” and “energy”. “nothing” means window is not applied; “population” means phonon states are discarded if $\frac{\partial \bar{n}}{\partial T} <$ windowPopulationLimit, where $\frac{\partial \bar{n}}{\partial T}$ is the Bose–Einstein distribution derivative.
Format: string
Required: no
Default: “nothing”

windowEnergyLimit

Description: Additional parameter for energy windowType. Specify two values $E_{min}$ and $E_{max}$ (in electronVolts) such that we discard all phonon states with energy outside of these bounds.
Format: list of doubles
Required: yes (if windowType = “energy”)

windowPopulationLimit

Description: Required if windowType = “population”. Cutoff values for discarding phonon states based on their equilibrium phonon occupation number, such that $\frac{\partial \bar{n}}{\partial T} <$ windowPopulationLimit.
Format: double
Required: no (optional if windowType = “population”)

maxIterationsBTE

Description: Maximum number of iterations for iterative and variational BTE solvers. If the maximum number of iterations is reached, the code will throw an error.
Format: int
Required: no
Default: 50

convergenceThresholdBTE

Description: Convergence criterion to stop iterative BTE solvers. The calculation is converged if the transport coefficients have a relative change smaller than convergenceThresholdBTE.
Format: double
Required: no
Default: 1.0e-5

dimensionality

Description: Input the dimensionality of the material. As a result, transport coefficients tensors will be of size (dim x dim), and units will be suitably scaled for the desired dimensionality.
Format: int
Required: no
Default: 3

constantRelaxationTime

Description: If specified, we solve the BTE with the constant relaxation time approximation, where the electron or phonon lifetime is set to this input value. (Fast but inaccurate!)
Format: double+units
Required: no

withIsotopeScattering

Description: Controls whether to include or not phonon-isotope scattering
Format: bool
Required: no
Default: true

masses

Description: User can specify a custom value of atomic masses. The masses must be ordered in the same way that atomic species are specified in the file phFC2FileName. If used, must specify the masses for all species. Defaults to the average mass for natural isotopic abundance.
Format: vector component
Required: no
Default: average mass at natural isotopic abundance

isotopeCouplings

Description: User can specify a list of custom atomic mass isotopic coupling parameters $g_2^s$ . See Theory section for a description. The values of isotopic scattering must be ordered in the same way that atomic species are specified in the file phFC2FileName. If used, must specify the couplings for all species. Defaults to the mass isotope scattering for natural isotopic abundance.
Format: vector component
Required: no
Default: natural isotopic abundance

boundaryLength

Description: If specified, includes the phonon-boundary scattering within the RTA approximation. Example: boundaryLength = 10 mum
Format: double+units
Required: no

electronH0Name

Description: For Wannier-interpolation-based calculations, electronH0Name must contain the path to the {prefix}_tb.dat file generated by Wannier90. For Fourier-interpolation-based calculations, electronH0Name must contain the path to the Quantum-ESPRESSO {outdir}/{prefix}.xml file generated by pw.x.
Format: string
Required: yes

dosMinEnergy

Description: Used in conjunction with dosMaxEnergy and dosDeltaEnergy to compute the Density of States every dosDeltaEnergy increments between dosMinEnergy and dosMaxEnergy.
Format: double+units
Required: yes (for dos calculation)

dosMaxEnergy

Description: Used in conjunction with dosMinEnergy and dosDeltaEnergy to compute the Density of States every dosDeltaEnergy increments between dosMinEnergy and dosMaxEnergy.
Format: double+units
Required: yes (for dos calculation)

dosDeltaEnergy

Description: Used in conjunction with dosMinEnergy and dosMaxEnergy to compute the Density of States every dosDeltaEnergy increments between dosMinEnergy and dosMaxEnergy.
Format: double+units
Required: yes (for dos calculation)

electronFourierCutoff

Description: A parameter controlling the search of lattice vectors used for the Fourier interpolation of the electronic band structure. In detail, the lattice vectors used for the Fourier interpolation are searched in a supercell of size electronFourierCutoff³ the primitive unit cell. Set it to at least 2.
Format: double
Required: yes (for electron Fourier DoS and bands)

begin/end crystal

Description: Specify the atomic species and atomic positions inside the crystal. This needs to be specified in some apps like WannierBands or WannierDos, as the output files of Wannier90 doesn’t provide all the information about the crystal.

Format: Namelist format, with atomic symbol and position coordinates in units of Angstroms. Example:

begin crystal
 Si 0.00000   0.00000   0.00000
 Si 1.34940   1.34940   1.34940
end crystal

Required: yes (for electron Wannier DoS and bands calculations)

begin/end point path

Description: Specify the path of wavectors in the Brillouin zone used in apps such as phononBands or phononLifetimes. Use the parameter deltaPath to control the number of wavevectors in each segment.

Format: Namelist format, as pairs of special point symbol and wavevector coordinates. Wavevector coordinates are in fractional coordinates with respect to the primitive reciprocal lattice vectors. Example:

begin point path
 L 0.50000  0.50000 0.5000 G 0.00000  0.00000 0.0000
 G 0.00000  0.00000 0.0000 X 0.50000  0.00000 0.5000
 X 0.50000 -0.50000 0.0000 K 0.37500 -0.37500 0.0000
 K 0.37500 -0.37500 0.0000 G 0.00000  0.00000 0.0000
end point path

Required: yes (for electron and phonon bands and lifetime apps)

dopings

Description: Specify a list of doping concentrations, in cm ^-3, to compute electronic properties at various doping concentrations. The chemical potentials corresponding to this doping concentrations will be computed.
Format: list of doubles
Required: yes (for electron transport and lifetime calculations, unless chemicalPotentials is specified)

chemicalPotentials

Description: Specify a list of chemical potentials to be used for the calculation of properties as a function of the chemical potential. If used in electron Wannier transport and scatteringMatrixInMemory=true, then only one value of chemical potentials can be specified. Values are in eV.
Format: list of doubles
Required: yes (unless minChemicalPotential, maxChemicalPotential, deltaChemicalPotential variables are present, or dopings are specified).

elphFileName

Description: Path to the file generated by the app elPhQeToPhoebe containing the electron-phonon coupling in the Wannier representation (e.g. {prefix}.phoebe.elph.dat)
Format: string
Required: yes (for electron transport and lifetime apps)

epaMinEnergy

Description: Specifies the minimum the energy bin value over which the electron-phonon coupling will be averaged for the EPA approximation post-processing in the elPhQeToPhoebe app.
Format: double
Required: yes (for EPA elPhQeToPhoebe runs)

epaMaxEnergy

Description: Specifies the maximum the energy bin value over which the electron-phonon coupling will be averaged for the EPA approximation post-processing in the elPhQeToPhoebe app.
Format: double
Required: yes (for EPA elPhQeToPhoebe runs)

epaNumBins

Description: The number of energy bins, ranging from epaMinEnergy to epaMaxEnergy used to average the electron-phonon matrix elements for EPA calculations in the elPhQeToPhoebe app.
Format: int
Required: yes (for EPA elPhQeToPhoebe runs)

epaSmearingEnergy

Description: Specifies the Gaussian width used in the moving least squares averaging procedure used to average the electron-phonon matrix elements for an EPA calculation.
Format: double
Required: yes (for EPA elPhQeToPhoebe runs)

epaFileName

Description: This is the path to the file *.phoebe.epa.dat, which is created by elPhQeToPhoebe.
Format: string
Required: yes (for EPA transport app)

epaEnergyStep

Description: The energy interval used to integrate the transport coefficients, i.e. lifetimes will be computed every epaEnergyStep energies.
Format: double
Required: yes (for EPA transport app)

epaEnergyRange

Description: EPA lifetimes will be computed for all energies in proximity of the chemical potential, i.e. for all energies such that $|\epsilon-\mu|<\text{epaEnergyRange}$ . This variable specifies that range.
Format: double
Required: yes (for EPA transport app)

deltaPath

Description: This variable controls how far apart are the wavevectors when a path in the Brillouin zone is specified, and it represents the distance (in Bohr) between wavevectors. Can be used when a path of wavevectors is specified with the begin/end point path key.
Default: 0.05 Bohr:sup:-1
Format: string
Required: no

elPhInterpolation

Description: Can be either “wannier” or “epa”. The first prepares the electron-phonon coupling for the transport calculation with Wannier interpolation (i.e. does the transformation from Bloch to Wannier representation). The second, prepares the electron-phonon coupling to be used with the EPA approximation.
Format: string
Required: yes (for elPhQeToPhoebe app)

wannier90Prefix

Description: Set to the same value of prefix in Wannier90. It’s used to locate the files {prefix}.eig generated by wannier90.x.
Format: string
Required: yes (for any electron app using Wannier interpolation)

quantumEspressoPrefix

Description: Set to the same value of prefix in Quantum-ESPRESSO. It’s used to locate the files {prefix}.dyn* or {prefix}.phoebe.*.dat generated by ph.x.
Format: string
Required: yes

fermiLevel

Description: Sets the fermi level of the ground state. Can be specified e.g. in Bands or DOS apps to specify an otherwise unknown fermi level. This quantity is read from file for transport calculations: this input parameter overwrites that value, use with caution.
Format: double+units
Required: no

numOccupiedStates

Description: Determines the number of occupied Kohn-Sham states at the ground state. The default value might be read from the electronH0Name (when this is the Quantum-ESPRESSO xml file) or the file with the el-ph interaction (so, the user may not need to specify it for transport calculations). This value controls where the Fermi level is set. The user alternatively can specify the fermiLevel (and numOccupiedStates will be computed from the Fermi level).
Format: double
Required: no

minChemicalPotential

Description: To be used together with maxChemicalPotential and deltaChemicalPotential, sets the code to compute properties at all chemical Potentials between minChemicalPotential and maxChemicalPotential in steps of deltaChemicalPotential. Can be exchanged with chemicalPotentials to instead manually specify the chemical potentials of the calculation.
Format: double
Required: yes (either specify minChemicalPotential, maxChemicalPotential, and deltaChemicalPotential or chemicalPotentials.

maxChemicalPotential

Description: To be used together with minChemicalPotential and deltaChemicalPotential, sets the code to compute properties at all chemical potentials between minChemicalPotential and maxChemicalPotential in steps of deltaChemicalPotential. Can be exchanged with chemicalPotentials to instead manually specify the chemical potentials of the calculation.
Format: double
Required: yes (either specify minChemicalPotential, maxChemicalPotential, and deltaChemicalPotential or chemicalPotentials)

deltaChemicalPotential

Description: To be used together with minChemicalPotential and maxChemicalPotential, sets the code to compute properties at all chemical Potentials between minChemicalPotential and maxChemicalPotential in steps of deltaChemicalPotential. Can be exchanged with chemicalPotentials to instead manually specify the chemical potentials of the calculation.
Format: double
Required: yes (either specify minChemicalPotential, maxChemicalPotential, and deltaChemicalPotential or chemicalPotentials)

minTemperature

Description: To be used together with maxTemperature and deltaTemperature, sets the code to compute observables at temperatures (in Kelvin) between minTemperature and maxTemperature in steps of deltaTemperature.
Format: double
Required: yes (either set minTemperature, maxTemperature, and deltaTemperature or temperatures)

maxTemperature

Description: To be used together with minTemperature and deltaTemperature, sets the code to compute observables at temperatures (in Kelvin) between minTemperature and maxTemperature in steps of deltaTemperature.
Format: double
Required: yes (either set minTemperature, maxTemperature, and deltaTemperature or temperatures)

deltaTemperature

Description: To be used together with minTemperature and maxTemperature, sets the code to compute observables at temperatures (in Kelvin) between minTemperature and maxTemperature in steps of deltaTemperature.
Format: double
Required: yes (either set minTemperature, maxTemperature, and deltaTemperature or temperatures)

useSymmetries

Description: When set to true, triggers the BTE to be computed only on the irreducible wedge of the Brillouin zone. For systems with several symmetries, this speeds up calculations. On the other hand, it may slow down the code for systems with few symmetries. If set to true, the viscosity is only computed at the RTA level.
Format: bool
Required: no
Default: false