# Manual¶

The complete WEST reference for input parameters.

Note

Not all input parameters listed below are mandatory. Check Quick Reference or Tutorials pages to see examples of input files.

WESTpy is a Python package, designed to assist users of the WEST code in pre- and post-process massively parallel calculations. Click here to know more.

The input file is given according to the YAML Notation (https://yaml.org/).

## input_west¶

qe_prefix
 Type string Default “pwscf” Description Prefix prepended to the Quantum ESPRESSO save folder.
west_prefix
 Type string Default “west” Description Prefix prepended to the WEST save and restart folders.
outdir
 Type string Default “./” Description Directory for: input, temporary, and output files.

## wstat_control¶

wstat_calculation
 Type string Default “S” Description Available options are: “S” : Start from scratch. “R” : Restart from an interrupted run. You should restart with the same number of cores, and images. “E” : Calculation of the response is external, i.e. outsourced to a server.
n_pdep_eigen
 Type int Default dynamically set to match the number of electrons Description Number of PDEP eigenpotentials.
n_pdep_times
 Type int Default 4 Description Maximum dimension of the search space = n_pdep_eigen * n_pdep_times.
n_pdep_maxiter
 Type int Default 100 Description Maximum number of iterations in PDEP.
n_dfpt_maxiter
 Type int Default 250 Description Maximum number of iterations in DFPT.
 Type int Default 0 Description Number of PDEP eigenpotentials that can be read from file.
n_steps_write_restart
 Type int Default 1 Description Available options are: If ( n_steps_write_restart > 0 ) A checkpoint is written every n_steps_write_restart iterations in the PDEP loop. If ( n_steps_write_restart <= 0 ) A checkpoint is NEVER written in the PDEP loop. Restart will not be possible.
trev_pdep
 Type float Default 0.001 Description Absolute convergence threshold for PDEP eigenvalues.
trev_pdep_rel
 Type float Default 0.1 Description Relative convergence threshold for PDEP eigenvalues.
tr2_dfpt
 Type float Default 1.e-12 Description Convergence threshold in DFPT. Note that in the first PDEP iterations a reduced threshold for DFPT could be used by the code in order to speed up the computation.
l_kinetic_only
 Type bool Default False Description If (True), then only the kinetic term in the Hamiltonian is kept.
l_minimize_exx_if_active
 Type bool Default False Description If (True), then the exact-exchange term in the Hamiltonian is computed with the cutoff of the wavefunction.
l_use_ecutrho
 Type bool Default False Description If (True), then the eigenpotentials are represented with ecutrho instead of ecutwfc.
qlist
 Type list of int Default [1,2,…,number of q-points] Description List of q-points to compute.

## wfreq_control¶

wfreq_calculation
 Type string Default “XWGQ” Description Available options are: “XWGQ” : Compute the QP corrections. “XwGQ” : Compute the QP corrections, restart from an interrupted / just read W run. “XwgQ” : Compute the QP corrections, restart from an interrupted / just read G run. “X” : Compute the HF corrections. “XWO” : Compute the optical properties. “XWGQP” : Compute the QP corrections, and plot spectral functions. “XWGQOP” : Compute all.
n_pdep_eigen_to_use
 Type int Default dynamically set to match the number of electrons Description Number of PDEP eigenvectors to use in Wfreq. They are read from previous Wstat run. This value cannot exceed n_pdep_eigen (defined in wstat_control) and is used to check the convergence of the calculation.
qp_bandrange
 Type 2-dim list of int Default [1,2] Description Compute the QP corrections from band qp_bandrange[0] to band qp_bandrange[1]. Used only when qp_bands is not set. If qp_bands is set, the value of qp_bandrange is discarded.
qp_bands
 Type list of int Default [0] Description List of bands to compute the QP corrections. If qp_bands is not set, qp_bands is determined from qp_bandrange: qp_bands = [qp_bandrange(1), qp_bandrange(1)+1, …, qp_bandrange(2)].
macropol_calculation
 Type string Default “N” Description Available options are: “N” : None. Choice valid for isolated systems. “C” : Include long-wavelength limit. Choice valid for condensed systems.
n_lanczos
 Type int Default 30 Description Number of Lanczos chains.
n_imfreq
 Type int Default 128 Description Number of frequecies used to sample the imaginary frequency axis in the range [0,ecut_imfreq].
n_refreq
 Type int Default 272 Description Number of frequecies used to sample the real frequency axis in the range [0,ecut_refreq].
ecut_imfreq
 Type float Default dynamically set to the cutoff energy of the density, read from the ground state Description Cutoff for the imaginary frequencies (in Ry).
ecut_refreq
 Type float Default 2.0 Description Cutoff for the real frequencies (in Ry).
wfreq_eta
 Type float Default 0.05 / 13.6056980659 Description Energy shift of the poles (in Ry).
n_secant_maxiter
 Type int Default 1 Description Maximum number of iterations in the secant solver.
trev_secant
 Type float Default 0.05 / 13.6056980659 Description Convergence energy threshold (in Ry) for the secant solver.
l_enable_lanczos
 Type bool Default True Description If (False), then Lanczos solvers are turned off.
l_enable_off_diagonal
 Type bool Default False Description If (False) then only the diagonal matrix elements of the $${G_0 W_0}$$ self-energy are evaluated (i.e., same band). If (True) then both the diagonal and off-diagonal matrix elements of the $${G_0 W_0}$$ self-energy are evaluated (mixing different bands). In this case the upper triangular part of the self-energy matrix is calculated and written to file according to $${ {\left[ \Sigma \right]}_{ij} = \frac{1}{2} \mathrm{Re} \; \left[ {\left[ \Sigma \right]}_{ij} (\epsilon^{\mathrm{QP}}_i) + {\left[ \Sigma \right]}_{ij}(\epsilon^{\mathrm{QP}}_j) \right] }$$. l_enable_off_diagonal can be set to True only when the Brillouin Zone is sampled at the $${\Gamma}$$-point.
l_enable_gwetot
 Type bool Default False Description Deprecated parameter.
o_restart_time
 Type float Default 0.0 Description Available options are: If ( o_restart_time == 0 ) A checkpoint is written at every iteration of the W and G loops. If ( o_restart_time > 0 ) A checkpoint is written every o_restart_time minutes in the W and G loops. If ( o_restart_time < 0 ) A checkpoint is NEVER written in the W and G loops. Restart will not be possible.
ecut_spectralf
 Type 2-dim list of float Default [-2.0,1.0] Description Energy cutoff (in Ry) for the real frequencies. Used when wfreq_caculation contains the runlevel “P”.
n_spectralf
 Type int Default 204 Description Number of frequecies used to plot the spectral function (runlevel “P”), sampling the interval [ecut_spectralf[0],ecut_spectralf[1]].

## westpp_control¶

westpp_calculation
 Type string Default “R” Description Available options are: “R” : Output rho, the electronic density. “W” : Output the electronic wavefunctions. “E” : Output the eigenpotentials. “S” : Output the screened exchange constant. “D” : Output the dipole matrix elements. “L” : Output the localization factor and the inverse participation ratio.
westpp_range
 Type list of int Default [1,2] Description Range for W, E, S, and D run.
westpp_format
 Type string Default “C” Description Available options for the output fortmat are: “c” : Cube. “x” : Planar average yz. “y” : Planar average xz. “z” : Planar average xy. “s” : Spherical average.
westpp_sign
 Type bool Default False Description If (True), then the sign of the wavefunction/eigenpotential is kept in the output file.
westpp_n_pdep_eigen_to_use
 Type int Default 1 Description Number PDEP eigenpotentials to read/use.
westpp_r0
 Type 3-dim list of floats (a vector) Default [0.0, 0.0, 0.0] Description Position of the center (in a.u.) for spherical average plot.
westpp_nr
 Type int Default 100 Description Number of points in the spherical average plot.
westpp_rmax
 Type float Default 1.0 Description Max radius (in a.u.) for the spherical average plot.
westpp_epsinfty
 Type float Default 1.0 Description Macroscopic relative dielectric constant. Used in the “S” runlevel.
westpp_box
 Type 6-dim list of floats (a vector) Default [0.0, 0.0, 0.0, 0.0, 0.0, 0.0] Description Box [x_0, x_1, y_0, y_1, z_0, z_1] (in a.u.) within which the localization factor is computed (the “L” runlevel).

## server_control¶

document
 Type jsonizable object Default “{}” Description The document is serialized into a JSON string and passed to the server (see West/Pytools/west_clientserver.py).