mirror of https://gitlab.com/QEF/q-e.git
799 lines
27 KiB
Modula-2
799 lines
27 KiB
Modula-2
input_description -distribution {Quantum Espresso} -package PWscf -program ph.x {
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toc {}
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intro {
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@b {Input data format:} { } = optional, [ ] = it depends, # = comment
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@b {Structure of the input data:}
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===============================================================================
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title_line
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@b &INPUTPH
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...
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@b /
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[ xq(1) xq(2) xq(3) ] @i {# if @ref ldisp != .true. and @ref qplot != .true.}
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[ nqs @i {# if @ref qplot == .true. }
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xq(1,i) xq(2,i) xq(3,1) nq(1)
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...
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xq(1,nqs) xq(2,nqs) xq(3,nqs) nq(nqs) ]
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[ atom(1) atom(2) ... atom(nat_todo) ] @i {# if @ref nat_todo was specified}
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}
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linecard {
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var title_line -type CHARACTER {
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info {
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Title of the job, i.e., a line that is reprinted on output.
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}
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}
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}
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namelist INPUTPH {
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dimension amass -start 1 -end ntyp -type REAL {
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default { 0.0 }
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info {
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Atomic mass [amu] of each atomic type.
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If not specified, masses are read from data file.
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}
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}
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var outdir -type CHARACTER {
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default {
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value of the @tt ESPRESSO_TMPDIR environment variable if set;
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@br current directory ('./') otherwise
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}
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info {
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Directory containing input, output, and scratch files;
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must be the same as specified in the calculation of
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the unperturbed system.
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}
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}
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var prefix -type CHARACTER {
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default { 'pwscf' }
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info {
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Prepended to input/output filenames; must be the same
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used in the calculation of unperturbed system.
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}
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}
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var niter_ph -type INTEGER {
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default { maxter=100 }
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info {
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Maximum number of iterations in a scf step. If you want
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more than 100, edit variable "maxter" in PH/phcom.f90
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}
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}
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var tr2_ph -type REAL {
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default { 1e-12 }
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info { Threshold for self-consistency. }
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}
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var alpha_mix(niter) -type REAL {
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default { alpha_mix(1)=0.7 }
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info {
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Mixing factor (for each iteration) for updating
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the scf potential:
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vnew(in) = alpha_mix*vold(out) + (1-alpha_mix)*vold(in)
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}
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}
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var nmix_ph -type INTEGER {
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default { 4 }
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info { Number of iterations used in potential mixing. }
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}
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var verbosity -type CHARACTER {
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default { 'default' }
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options {
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info { Options are: }
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opt -val {'debug', 'high', 'medium'} { verbose output }
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opt -val {'low', 'default', 'minimal'} { short output }
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}
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}
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var reduce_io -type LOGICAL {
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default { .false. }
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info { Reduce I/O to the strict minimum. }
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}
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var max_seconds -type REAL {
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default { 1.d7 }
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info { Maximum allowed run time before the job stops smoothly. }
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}
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var fildyn -type CHARACTER {
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default { 'matdyn' }
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info { File where the dynamical matrix is written. }
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}
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var fildrho -type CHARACTER {
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default { ' ' }
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info { File where the charge density responses are written. Note that the file
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will actually be saved as ${outdir}/_ph0/${prefix}.${fildrho}1
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where ${outdir}, ${prefix} and ${fildrho} are the values of the
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corresponding input variables }
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}
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var fildvscf -type CHARACTER {
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default { ' ' }
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info {
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File where the the potential variation is written
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(for later use in electron-phonon calculation, see also fildrho).
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}
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}
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var epsil -type LOGICAL {
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default { .false. }
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info {
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If .true. in a q=0 calculation for a non metal the
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macroscopic dielectric constant of the system is
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computed. Do not set @ref epsil to .true. if you have a
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metallic system or q/=0: the code will complain and stop.
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}
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}
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var lrpa -type LOGICAL {
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default { .false. }
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info {
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If .true. the dielectric constant is calculated at the
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RPA level with DV_xc=0.
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}
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}
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var lnoloc -type LOGICAL {
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default { .false. }
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info {
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If .true. the dielectric constant is calculated without
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local fields, i.e. by setting DV_H=0 and DV_xc=0.
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}
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}
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var trans -type LOGICAL {
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default { .true. }
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info {
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If .true. the phonons are computed.
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If @ref trans .and. @ref epsil are .true. effective charges are
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calculated.
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}
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}
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var lraman -type LOGICAL {
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default { .false. }
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info {
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If .true. calculate non-resonant Raman coefficients
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using second-order response as in:
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M. Lazzeri and F. Mauri, PRL 90, 036401 (2003).
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}
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}
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group {
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label { Optional variables for Raman: }
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var eth_rps -type REAL {
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default { 1.0d-9 }
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info { Threshold for calculation of Pc R |psi>. }
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}
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var eth_ns -type REAL {
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default { 1.0e-12 }
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info { Threshold for non-scf wavefunction calculation. }
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}
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var dek -type REAL {
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default { 1.0e-3 }
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info { Delta_xk used for wavefunction derivation wrt k.}
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}
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}
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var recover -type LOGICAL {
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default { .false. }
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info { If .true. restart from an interrupted run.}
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}
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var low_directory_check -type LOGICAL {
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default { .false. }
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info { If .true. search in the phsave directory only the
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quantities requested in input.}
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}
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var only_init -type LOGICAL {
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default { .false. }
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info {
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If .true. only the bands and other initialization quantities are calculated.
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(used for GRID parallelization)}
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}
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var qplot -type LOGICAL {
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default { .false. }
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info { If .true. a list of q points is read from input.}
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}
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var q2d -type LOGICAL {
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default { .false. }
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info {
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If .true. three q points and relative weights are
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read from input. The three q points define the rectangle
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q(:,1) + l (q(:,2)-q(:,1)) + m (q(:,3)-q(:,1)) where
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0< l,m < 1. The weights are integer and those of points two
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and three are the number of points in the two directions.
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}
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}
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var q_in_band_form -type LOGICAL {
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default { .false. }
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info {
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This flag is used only when qplot is .true. and q2d is
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.false.. When .true. each couple of q points q(:,i+1) and
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q(:,i) define the line from q(:,i) to q(:,i+1) and nq
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points are generated along that line. nq is the weigth of
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q(:,i). When .false. only the list of q points given as
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input is calculated. The weights are not used.
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}
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}
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var electron_phonon -type CHARACTER {
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default { ' ' }
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options {
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info {
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Options are:
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}
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opt -val 'simple' {
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Electron-phonon lambda coefficients are computed
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for a given q and a grid of k-points specified by
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the variables nk1, nk2, nk3, k1, k2, k3.
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}
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opt -val 'interpolated' {
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Electron-phonon is calculated by interpolation
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over the Brillouin Zone as in M. Wierzbowska, et
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al. arXiv:cond-mat/0504077
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}
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opt -val 'lambda_tetra' {
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The electron-phonon coefficient \lambda_{q \nu}
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is calculated with the optimized tetrahedron method.
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}
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opt -val 'gamma_tetra' {
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The phonon linewidth \gamma_{q \nu} is calculated
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from the electron-phonon interactions
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using the optimized tetrahedron method.
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}
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opt -val 'epa' {
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Electron-phonon coupling matrix elements are written
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to file prefix.epa.k for further processing by program
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epa.x which implements electron-phonon averaged (EPA)
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approximation as described in G. Samsonidze & B. Kozinsky,
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Adv. Energy Mater. 2018, 1800246 doi:10.1002/aenm.201800246
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arXiv:1511.08115
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}
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info {
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For metals only, requires gaussian smearing.
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If @ref trans=.true., the lambdas are calculated in the same
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run, using the same k-point grid for phonons and lambdas.
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If @ref trans=.false., the lambdas are calculated using
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previously saved DeltaVscf in @ref fildvscf, previously saved
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dynamical matrix, and the present punch file. This allows
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the use of a different (larger) k-point grid.
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}
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}
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}
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var el_ph_nsigma -type INTEGER {
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default { 10 }
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info {
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The number of double-delta smearing values used in an
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electron-phonon coupling calculation.
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}
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}
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var el_ph_sigma -type REAL {
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default { 0.02 }
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info {
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The spacing between double-delta smearing values used in
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an electron-phonon coupling calculation.
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}
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}
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var lshift_q -type LOGICAL {
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default { .false. }
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info {
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Use a wave-vector grid displaced by half a grid step
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in each direction - meaningful only when ldisp is .true.
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When this option is set, the q2r.x code cannot be used.
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}
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}
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var zeu -type LOGICAL {
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default { zeu=@ref epsil }
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info {
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If .true. in a q=0 calculation for a non metal the
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effective charges are computed from the dielectric
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response. This is the default algorithm. If @ref epsil=.true.
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and @ref zeu=.false. only the dielectric tensor is calculated.
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}
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}
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var zue -type LOGICAL {
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default { .false. }
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info {
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If .true. in a q=0 calculation for a non metal the
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effective charges are computed from the phonon
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density responses. This is an alternative algorithm,
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different from the default one (if @ref trans .and. @ref epsil )
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The results should be the same within numerical noise.
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}
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}
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var elop -type LOGICAL {
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default { .false. }
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info {
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If .true. calculate electro-optic tensor.
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}
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}
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var fpol -type LOGICAL {
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default { .false. }
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info {
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If .true. calculate dynamic polarizabilities
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Requires @ref epsil=.true. ( experimental stage:
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see example09 for calculation of methane ).
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}
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}
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var ldisp -type LOGICAL {
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default { .false. }
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info {
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If .true. the run calculates phonons for a grid of
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q-points specified by @ref nq1, @ref nq2, @ref nq3 - for direct
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calculation of the entire phonon dispersion.
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}
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}
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var nogg -type LOGICAL {
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default { .false. }
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info {
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If .true. disable the "gamma_gamma" trick used to speed
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up calculations at q=0 (phonon wavevector) if the sum over
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the Brillouin Zone includes k=0 only. The gamma_gamma
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trick exploits symmetry and acoustic sum rule to reduce
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the number of linear response calculations to the strict
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minimum, as it is done in code phcg.x.
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}
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}
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var asr -type LOGICAL {
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default { .false. }
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info {
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Apply Acoustic Sum Rule to dynamical matrix, effective charges
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Works only in conjunction with "gamma_gamma" tricks (see above)
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}
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}
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var ldiag -type LOGICAL {
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default { .false. }
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info {
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If .true. forces the diagonalization of the dynamical
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matrix also when only a part of the dynamical matrix
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has been calculated. It is used together with @ref start_irr
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and @ref last_irr. If all modes corresponding to a
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given irreducible representation have been calculated,
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the phonon frequencies of that representation are
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correct. The others are zero or wrong. Use with care.
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}
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}
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var lqdir -type LOGICAL {
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default { .false. }
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info {
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If .true. ph.x creates inside outdir a separate subdirectory
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for each q vector. The flag is set to .true. when @ref ldisp=.true.
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and @ref fildvscf /= ' ' or when an electron-phonon
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calculation is performed. The induced potential is saved
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separately for each q inside the subdirectories.
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}
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}
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var search_sym -type LOGICAL {
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default { .true. }
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info {
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Set it to .false. if you want to disable the mode
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symmetry analysis.
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}
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}
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vargroup -type INTEGER {
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var nq1
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var nq2
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var nq3
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default { 0,0,0 }
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info {
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Parameters of the Monkhorst-Pack grid (no offset) used
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when @ref ldisp=.true. Same meaning as for nk1, nk2, nk3
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in the input of pw.x.
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}
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}
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vargroup -type INTEGER {
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var nk1
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var nk2
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var nk3
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var k1
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var k2
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var k3
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default { 0,0,0,0,0,0 }
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info {
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When these parameters are specified the phonon program
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runs a pw non-self consistent calculation with a different
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k-point grid thant that used for the charge density.
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This occurs even in the Gamma case.
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nk1,nk2,nk3 are the parameters of the Monkhorst-Pack grid
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with offset determined by k1,k2,k3.
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}
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}
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var diagonalization -type CHARACTER {
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default { 'david' }
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options {
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info {
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Diagonalization method for the non-SCF calculations.
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}
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opt -val 'david' {
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Davidson iterative diagonalization with overlap matrix
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(default). Fast, may in some rare cases fail.
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}
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opt -val 'cg' {
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Conjugate-gradient-like band-by-band diagonalization.
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Slower than 'david' but uses less memory and is
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(a little bit) more robust.
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}
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}
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}
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var read_dns_bare -type LOGICAL {
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default { .false. }
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info {
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If .true. the PH code tries to read three files in the DFPT+U
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calculation: dns_orth, dns_bare, d2ns_bare.
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dns_orth and dns_bare are the first-order variations of
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the occupation matrix, while d2ns_bare is the second-order
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variation of the occupation matrix. These matrices are
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computed only once during the DFPT+U calculation. However,
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their calculation (especially of d2ns_bare) is computationally
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expensive, this is why they are written to file and then can be
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read (e.g. for restart) in order to save time.
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}
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}
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var ldvscf_interpolate -type LOGICAL {
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default { .false. }
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info {
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If .true., use Fourier interpolation of phonon potential
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to compute the induced part of phonon potential at each
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q point. Results of a dvscf_q2r.x run is needed.
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Requires @ref trans = .false..
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}
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}
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group {
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label { Optional variables for dvscf interpolation: }
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var wpot_dir -type CHARACTER {
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default { outdir // 'w_pot/' }
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info {
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Directory where the w_pot binary files are written.
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Must be the same with wpot_dir used in dvscf_q2r.x.
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The real space potential files are stored in wpot_dir
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with names ${prefix}.wpot.irc${irc}//"1".
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}
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}
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var do_long_range -type LOGICAL {
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default { .false. }
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info {
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If .true., add the long-range part of the potential
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to the Fourier interpolated potential as in:
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S. Ponce et al, J. Chem. Phys. 143, 102813 (2015).
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Reads dielectric matrix and Born effective charges from
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the ${wpot_dir}/tensors.dat file, written in dvscf_q2r.x.
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Currently, only the dipole (Frohlich) part is implemented.
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The quadrupole part is not implemented.
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}
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}
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var do_charge_neutral -type LOGICAL {
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default { .false. }
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info {
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If .true., impose charge neutrality on the Born effective
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charges. Used only if @ref do_long_range = .true..
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}
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}
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}
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group {
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label { Specification of irreducible representation }
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var start_irr -type INTEGER {
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default { 1 }
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see { last_irr }
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info {
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Perform calculations only from @ref start_irr to @ref last_irr
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irreducible representations.
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IMPORTANT:
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* @ref start_irr must be <= 3*nat
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* do not specify @ref nat_todo together with
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@ref start_irr, @ref last_irr
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}
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}
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var last_irr -type INTEGER {
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default { 3*nat }
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see { start_irr }
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info {
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Perform calculations only from @ref start_irr to @ref last_irr
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irreducible representations.
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IMPORTANT:
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* @ref start_irr must be <= 3*nat
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* do not specify @ref nat_todo together with
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@ref start_irr, @ref last_irr
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}
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}
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var nat_todo -type INTEGER {
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default { 0, i.e. displace all atoms }
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info {
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|
Choose the subset of atoms to be used in the linear response
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calculation: @ref nat_todo atoms, specified in input (see below)
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|
are displaced. Can be used to estimate modes for a molecule
|
|
adsorbed over a surface without performing a full fledged
|
|
calculation. Use with care, at your own risk, and be aware
|
|
that this is an approximation and may not work.
|
|
IMPORTANT:
|
|
* @ref nat_todo <= nat
|
|
* if linear-response is calculated for a given atom, it
|
|
should also be done for all symmetry-equivalent atoms,
|
|
or else you will get incorrect results
|
|
}
|
|
}
|
|
|
|
var modenum -type INTEGER {
|
|
default { 0 }
|
|
info {
|
|
For single-mode phonon calculation : modenum is the index of the
|
|
irreducible representation (irrep) into which the reducible
|
|
representation formed by the 3*nat atomic displacements are
|
|
decomposed in order to perform the phonon calculation.
|
|
Note that a single-mode calculation will not give you the
|
|
frequency of a single phonon mode: in general, the selected
|
|
"modenum" is not an eigenvector. What you get on output is
|
|
a column of the dynamical matrix.
|
|
}
|
|
}
|
|
}
|
|
|
|
group {
|
|
label { q-point specification }
|
|
|
|
var start_q -type INTEGER {
|
|
default { 1 }
|
|
see { last_q }
|
|
info {
|
|
Used only when ldisp=.true..
|
|
Computes only the q points from @ref start_q to @ref last_q.
|
|
|
|
IMPORTANT:
|
|
* @ref start_q must be <= @ref nqs (number of q points found)
|
|
* do not specify @ref nat_todo together with
|
|
@ref start_q, @ref last_q
|
|
}
|
|
}
|
|
|
|
var last_q -type INTEGER {
|
|
default { number of q points }
|
|
see { start_q }
|
|
info {
|
|
Used only when @ref ldisp=.true..
|
|
Computes only the q points from @ref start_q to @ref last_q.
|
|
|
|
IMPORTANT
|
|
* @ref last_q must be <= @ref nqs (number of q points)
|
|
* do not specify @ref nat_todo together with
|
|
@ref start_q, @ref last_q
|
|
}
|
|
}
|
|
|
|
var dvscf_star -type STRUCTURE {
|
|
default { disabled }
|
|
info {
|
|
It contains the following components:
|
|
|
|
@b dvscf_star%open (logical, default: .false.)
|
|
@b dvscf_star%dir (character, default: outdir//"Rotated_DVSCF" or the
|
|
ESPRESSO_FILDVSCF_DIR environment variable)
|
|
@b dvscf_star%ext (character, default: "dvscf") the extension to use
|
|
for the name of the output files, see below
|
|
@b dvscf_star%basis (character, default: "cartesian") the basis on which
|
|
the rotated dvscf will be saved
|
|
@b dvscf_star%pat (logical, default: false) save an optional file with the
|
|
displacement patterns and q vector for each dvscf file
|
|
|
|
IF dvscf_star%open is .true. use symmetry to compute and store the variation
|
|
of the self-consistent potential on every q* in the star of the present q.
|
|
|
|
The rotated dvscf will then be stored in directory dvscf_star%dir with name
|
|
prefix.dvscf_star%ext.q_name//"1". Where q_name is derived from the coordinates
|
|
of the q-point, expressed as fractions in crystalline coordinates
|
|
(notice that ph.x reads q-points in cartesian coordinates).
|
|
E.g. q_cryst= (0, 0.5, -0.25) -> q_name = "0_1o2_-1o4"
|
|
|
|
The dvscf can be represented on a basis of cartesian 1-atom displacements
|
|
(dvscf_star%basis='cartesian') or on the basis of the modes at the rotated q-point
|
|
(dvscf_star%basis='modes'). Notice that the el-ph wannier code requires 'cartesian'.
|
|
Each dvscf file comes with a corresponding pattern file with an additional ".pat"
|
|
suffix; this file contains information about the basis and the q-point of the dvscf.
|
|
|
|
Note: rotating dvscf can require a large amount of RAM memory and can be i/o
|
|
intensive; in its current implementation all the operations are done
|
|
on a single processor.
|
|
Note2: this feature is currently untested with image parallelisation.
|
|
}
|
|
}
|
|
|
|
var drho_star -type STRUCTURE {
|
|
see {dvscf_star }
|
|
default { disabled }
|
|
info {
|
|
It contains the following components:
|
|
|
|
@b drho_star%open (logical, default: .false.)
|
|
@b drho_star%dir (character, default: outdir//"Rotated_DRHO" or the
|
|
ESPRESSO_FILDRHO_DIR environment variable)
|
|
@b drho_star%ext (character, default: "drho") the extension to use
|
|
for the name of the output files, see below
|
|
@b drho_star%basis (character, default: "modes") the basis on which
|
|
the rotated drho will be saved
|
|
@b drho_star%pat (logical, default: true) save an optional file with the
|
|
displacement patterns and q vector for each drho file
|
|
|
|
Like @ref dvscf_star, but for the perturbation of the charge density.
|
|
Notice that the defaults are different.
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
choose {
|
|
when -test "ldisp != .true. and qplot != .true." {
|
|
|
|
linecard {
|
|
list xq_list -type REAL {
|
|
format { xq(1) xq(2) xq(3) }
|
|
info {
|
|
The phonon wavevector, in units of 2pi/a0
|
|
(a0 = lattice parameter).
|
|
Not used if @ref ldisp=.true. or @ref qplot=.true.
|
|
}
|
|
}
|
|
}
|
|
}
|
|
elsewhen -test "qplot == .true." {
|
|
|
|
label { Specification of q points when @ref qplot == .true. }
|
|
|
|
card qPointsSpecs -nameless 1 {
|
|
syntax {
|
|
line {
|
|
var nqs -type INTEGER {
|
|
info { Number of q points in the list. Used only if @ref qplot=.true.
|
|
}
|
|
}
|
|
}
|
|
|
|
table qPoints {
|
|
rows -start 1 -end nqs {
|
|
colgroup -type REAL {
|
|
info {
|
|
q-point coordinates; used only with @ref ldisp=.true. and qplot=.true.
|
|
The phonon wavevector, in units of 2pi/a0 (a0 = lattice parameter).
|
|
The meaning of these q points and their weights nq depend on the
|
|
flags q2d and q_in_band_form. (NB: nq is integer)
|
|
}
|
|
col xq1
|
|
col xq2
|
|
col xq3
|
|
}
|
|
col nq -type INTEGER {
|
|
info {
|
|
The weight of the q-point; the meaning of nq depends
|
|
on the flags q2d and q_in_band_form. }
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
choose {
|
|
when -test "nat_todo was specified" {
|
|
linecard {
|
|
list nat_todo_list -type INTEGER {
|
|
format { atom(1) atom(2) ... atom(nat_todo) }
|
|
info {
|
|
Contains the list of indices of atoms used in the
|
|
calculation if @ref nat_todo is specified.
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
section -title { ADDITIONAL INFORMATION } {
|
|
|
|
text {
|
|
|
|
NB: The program ph.x writes on the tmp_dir/_ph0/{prefix}.phsave directory
|
|
a file for each representation of each q point. This file is called
|
|
dynmat.#iq.#irr.xml where #iq is the number of the q point and #irr
|
|
is the number of the representation. These files contain the
|
|
contribution to the dynamical matrix of the irr representation for the
|
|
iq point.
|
|
|
|
If recover=.true. ph.x does not recalculate the
|
|
representations already saved in the tmp_dir/_ph0/{prefix}.phsave
|
|
directory. Moreover ph.x writes on the files patterns.#iq.xml in the
|
|
tmp_dir/_ph0/{prefix}.phsave directory the displacement patterns that it
|
|
is using. If recover=.true. ph.x does not recalculate the
|
|
displacement patterns found in the tmp_dir/_ph0/{prefix}.phsave directory.
|
|
|
|
This mechanism allows:
|
|
|
|
1) To recover part of the ph.x calculation even if the recover file
|
|
or files are corrupted. You just remove the _ph0/{prefix}.recover
|
|
files from the tmp_dir directory. You can also remove all the _ph0
|
|
files and keep only the _ph0/{prefix}.phsave directory.
|
|
|
|
2) To split a phonon calculation into several jobs for different
|
|
machines (or set of nodes). Each machine calculates a subset of
|
|
the representations and saves its dynmat.#iq.#irr.xml files on
|
|
its tmp_dir/_ph0/{prefix}.phsave directory. Then you collect all the
|
|
dynmat.#iq.#irr.xml files in one directory and run ph.x to
|
|
collect all the dynamical matrices and diagonalize them.
|
|
|
|
NB: To split the q points in different machines, use the input
|
|
variables start_q and last_q. To split the irreducible
|
|
representations, use the input variables @ref start_irr, @ref last_irr. Please
|
|
note that different machines will use, in general, different
|
|
displacement patterns and it is not possible to recollect partial
|
|
dynamical matrices generated with different displacement patterns. A
|
|
calculation split into different machines will run as follows: A
|
|
preparatory run of ph.x with @ref start_irr=0, @ref last_irr=0 produces the sets
|
|
of displacement patterns and save them on the patterns.#iq.xml files.
|
|
These files are copied in all the tmp_dir/_ph0/{prefix}.phsave directories
|
|
of the machines where you plan to run ph.x. ph.x is run in different
|
|
machines with complementary sets of start_q, last_q, @ref start_irr and
|
|
@ref last_irr variables. All the files dynmat.#iq.#irr.xml are
|
|
collected on a single tmp_dir/_ph0/{prefix}.phsave directory (remember to
|
|
collect also dynmat.#iq.0.xml). A final run of ph.x in this
|
|
machine collects all the data contained in the files and diagonalizes
|
|
the dynamical matrices. This is done requesting a complete dispersion
|
|
calculation without using start_q, last_q, @ref start_irr, or @ref last_irr.
|
|
See an example in examples/GRID_example.
|
|
|
|
On parallel machines the q point and the irreps calculations can be split
|
|
automatically using the -nimage flag. See the phonon user guide for further
|
|
information.
|
|
|
|
}
|
|
}
|
|
}
|