# 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.

## input_west¶

qe_prefix
Type: string “calc” Prefix prepended to the QuantumEspresso save folder.
west_prefix
Type: string “west” Prefix prepended to the WEST save and restart folder.
outdir
Type: string Value of the ESPRESSO_TMPDIR environment variable if set; current directory (“./”) otherwise Input, temporary, output files are found in this directory.

## wstat_control¶

wstat_calculation
Type: string “S” Available options are: “S” : Start from scratch “R” : Restart from an interrupted run. You should restart with the same number of cores, and images.
n_pdep_eigen
Type: int 1 Number of PDEP eigenpotentials.
n_pdep_times
Type: int 4 Maximum dimension of the search space = n_pdep_eigen * n_pdep_times.
n_pdep_maxiter
Type: int 100 Maximum number of iterations in PDEP.
n_dfpt_maxiter
Type: int 250 Maximum number of iterations in DFPT.
n_pdep_read_from_file
Type: int 0 Number of PDEP eigenpotentials that can be read from file.
trev_pdep
Type: float 0.001 Absolute convergence threshold in the PDEP eigenvalues.
trev_pdep_rel
Type: float 0.1 Relative convergence threshold in the PDEP eigenvalues.
tr2_dfpt
Type: float 1e-12 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_minimize_exx_if_active
Type: boolean False If (True), then the exact-exchange term in the Hamiltonian is computed with the cutoff of the wavefunction.
l_kinetic_only
Type: boolean False If (True), then only the kinetic term in the Hamiltonian is kept.
l_use_ecutrho
Type: boolean False If (True), then the eigenpotentials are represented with ecutrho instead of ecutwfc.
qlist
Type: list of int [1,2,…,number of q-points] List of q-points to compute.

## wfreq_control¶

wfreq_calculation
Type: string “XWGQ” 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 2 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: list of int [1,2] Compute the QP corrections from band qp_bandrange[0] to band qp_bandrange[1].
macropol_calculation
Type: string “N” Available options are: “N” : None. Choice valid for isolated systems. “C” : Include long-wavelength limit. Choice valid for condensed systems.
n_lanczos
Type: int 30 Number of Lanczos chains.
n_imfreq
Type: int 128 Number of frequecies used to sample the imaginary frequency axis in the range [0,ecut_imfreq].
n_refreq
Type: int 10 Number of frequecies used to sample the real frequency axis in the range [0,ecut_refreq].
ecut_imfreq
Type: float Cut of the density, read from the ground state Cutoff for the imaginary frequencies (in Ry).
ecut_refreq
Type: float 2.0 Cutoff for the real frequencies (in Ry).
wfreq_eta
Type: float 0.003675 Energy shift of the poles (in Ry).
n_secant_maxiter
Type: int 1 Maximum number of iterations in the secant solver.
trev_secant
Type: float 0.003675 Convergence energy threshold (in Ry) for the secant solver.
l_enable_lanczos
Type: boolean True If (False), then Lanczos solvers are turned off.
l_enable_gwetot
Type: boolean False Deprecated parameter.
o_restart_time
Type: float 0.0 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: list of float [-2.0,2.0] Energy cutoff (in Ry) for the real frequencies. Used when wfreq_caculation contains the runlevel “P”.
n_spectralf
Type: int 10 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 “R” Available options are: “R” : Output rho, the electronic density. “W” : Output the electronic wavefunctions. “E” : Output the eigenpotentials. “S” : Output the screened exchange constant.
westpp_range
Type: list of int [1,2] Range for W, E, and S run.
westpp_format
Type: string “C” 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: boolean False If (True), then the sign of the wavefunction/eigenpotential is kept in the output file.
westpp_n_pdep_eigen_to_use
Type: int 1 Number PDEP eigenpotentials to read/use.
westpp_r0
Type: 3-dim list of floats (a vector) [0.0, 0.0, 0.0] Position of the center (in a.u.) for spherical average plot.
westpp_nr
Type: int 100 Number of points in the spherical average plot.
westpp_rmax
Type: float 1.0 Max radius (in a.u.) for the spherical average plot.
westpp_epsinfty
Type: float 1.0 Macroscopic relative dielectric constant. Used in the “S” runlevel.