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|
*** FILE AUTOMATICALLY CREATED: DO NOT EDIT, CHANGES WILL BE LOST ***
------------------------------------------------------------------------
INPUT FILE DESCRIPTION
Program: ph.x / PWscf / Quantum Espresso (version: 6.6)
------------------------------------------------------------------------
Input data format: { } = optional, [ ] = it depends, # = comment
Structure of the input data:
===============================================================================
title_line
&INPUTPH
...
/
[ xq(1) xq(2) xq(3) ] # if "ldisp" != .true. and "qplot" != .true.
[ nqs # if "qplot" == .true.
xq(1,i) xq(2,i) xq(3,1) nq(1)
...
xq(1,nqs) xq(2,nqs) xq(3,nqs) nq(nqs) ]
[ atom(1) atom(2) ... atom(nat_todo) ] # if "nat_todo" was specified
========================================================================
Line of input:
title_line
DESCRIPTION OF ITEMS:
+--------------------------------------------------------------------
Variable: title_line
Type: CHARACTER
Description: Title of the job, i.e., a line that is reprinted on output.
+--------------------------------------------------------------------
===End of line-of-input=================================================
========================================================================
NAMELIST: &INPUTPH
+--------------------------------------------------------------------
Variable: amass(i), i=1,ntyp
Type: REAL
Default: 0.0
Description: Atomic mass [amu] of each atomic type.
If not specified, masses are read from data file.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: outdir
Type: CHARACTER
Default: value of the ESPRESSO_TMPDIR environment variable if set;
current directory ('./') otherwise
Description: Directory containing input, output, and scratch files;
must be the same as specified in the calculation of
the unperturbed system.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: prefix
Type: CHARACTER
Default: 'pwscf'
Description: Prepended to input/output filenames; must be the same
used in the calculation of unperturbed system.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: niter_ph
Type: INTEGER
Default: maxter=100
Description: Maximum number of iterations in a scf step. If you want
more than 100, edit variable "maxter" in PH/phcom.f90
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: tr2_ph
Type: REAL
Default: 1e-12
Description: Threshold for self-consistency.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: alpha_mix(niter)
Type: REAL
Default: alpha_mix(1)=0.7
Description: Mixing factor (for each iteration) for updating
the scf potential:
vnew(in) = alpha_mix*vold(out) + (1-alpha_mix)*vold(in)
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: nmix_ph
Type: INTEGER
Default: 4
Description: Number of iterations used in potential mixing.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: verbosity
Type: CHARACTER
Default: 'default'
Description:
Options are:
'debug', 'high', 'medium' :
verbose output
'low', 'default', 'minimal' :
short output
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: reduce_io
Type: LOGICAL
Default: .false.
Description: Reduce I/O to the strict minimum.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: max_seconds
Type: REAL
Default: 1.d7
Description: Maximum allowed run time before the job stops smoothly.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: fildyn
Type: CHARACTER
Default: 'matdyn'
Description: File where the dynamical matrix is written.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: fildrho
Type: CHARACTER
Default: ' '
Description: File where the charge density responses are written. Note that the file
will actually be saved as ${outdir}/_ph0/${prefix}.${fildrho}1
where ${outdir}, ${prefix} and ${fildrho} are the values of the
corresponding input variables
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: fildvscf
Type: CHARACTER
Default: ' '
Description: File where the the potential variation is written
(for later use in electron-phonon calculation, see also fildrho).
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: epsil
Type: LOGICAL
Default: .false.
Description: If .true. in a q=0 calculation for a non metal the
macroscopic dielectric constant of the system is
computed. Do not set "epsil" to .true. if you have a
metallic system or q/=0: the code will complain and stop.
Note: the input value of "epsil" will be ignored if "ldisp"=.true.
(the code will automatically set "epsil" to .false. for metals,
to .true. for insulators: see routine PHonon/PH/prepare_q.f90).
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: lrpa
Type: LOGICAL
Default: .false.
Description: If .true. the dielectric constant is calculated at the
RPA level with DV_xc=0.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: lnoloc
Type: LOGICAL
Default: .false.
Description: If .true. the dielectric constant is calculated without
local fields, i.e. by setting DV_H=0 and DV_xc=0.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: trans
Type: LOGICAL
Default: .true.
Description: If .true. the phonons are computed.
If "trans" .and. "epsil" are .true. effective charges are
calculated.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: lraman
Type: LOGICAL
Default: .false.
Description: If .true. calculate non-resonant Raman coefficients
using second-order response as in:
M. Lazzeri and F. Mauri, PRL 90, 036401 (2003).
+--------------------------------------------------------------------
///---
OPTIONAL VARIABLES FOR RAMAN:
+--------------------------------------------------------------------
Variable: eth_rps
Type: REAL
Default: 1.0d-9
Description: Threshold for calculation of Pc R |psi>.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: eth_ns
Type: REAL
Default: 1.0e-12
Description: Threshold for non-scf wavefunction calculation.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: dek
Type: REAL
Default: 1.0e-3
Description: Delta_xk used for wavefunction derivation wrt k.
+--------------------------------------------------------------------
\\\---
+--------------------------------------------------------------------
Variable: recover
Type: LOGICAL
Default: .false.
Description: If .true. restart from an interrupted run.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: low_directory_check
Type: LOGICAL
Default: .false.
Description: If .true. search in the phsave directory only the
quantities requested in input.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: only_init
Type: LOGICAL
Default: .false.
Description: If .true. only the bands and other initialization quantities are calculated.
(used for GRID parallelization)
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: qplot
Type: LOGICAL
Default: .false.
Description: If .true. a list of q points is read from input.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: q2d
Type: LOGICAL
Default: .false.
Description: If .true. three q points and relative weights are
read from input. The three q points define the rectangle
q(:,1) + l (q(:,2)-q(:,1)) + m (q(:,3)-q(:,1)) where
0< l,m < 1. The weights are integer and those of points two
and three are the number of points in the two directions.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: q_in_band_form
Type: LOGICAL
Default: .false.
Description: This flag is used only when qplot is .true. and q2d is
.false.. When .true. each couple of q points q(:,i+1) and
q(:,i) define the line from q(:,i) to q(:,i+1) and nq
points are generated along that line. nq is the weigth of
q(:,i). When .false. only the list of q points given as
input is calculated. The weights are not used.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: electron_phonon
Type: CHARACTER
Default: ' '
Description:
Options are:
'simple' :
Electron-phonon lambda coefficients are computed
for a given q and a grid of k-points specified by
the variables nk1, nk2, nk3, k1, k2, k3.
'interpolated' :
Electron-phonon is calculated by interpolation
over the Brillouin Zone as in M. Wierzbowska, et
al. arXiv:cond-mat/0504077
'lambda_tetra' :
The electron-phonon coefficient \lambda_{q \nu}
is calculated with the optimized tetrahedron method.
'gamma_tetra' :
The phonon linewidth \gamma_{q \nu} is calculated
from the electron-phonon interactions
using the optimized tetrahedron method.
'epa' :
Electron-phonon coupling matrix elements are written
to file prefix.epa.k for further processing by program
epa.x which implements electron-phonon averaged (EPA)
approximation as described in G. Samsonidze & B. Kozinsky,
Adv. Energy Mater. 2018, 1800246 doi:10.1002/aenm.201800246
arXiv:1511.08115
'ahc' :
Quantities required for the calculation of phonon-induced
electron self-energy are computed and written to the directory
"ahc_dir". The output files can be read by postahc.x for
the calculation of electron self-energy.
Available for both metals and insulators.
"trans"=.false. is required.
For metals only, requires gaussian smearing (except for 'ahc').
If "trans"=.true., the lambdas are calculated in the same
run, using the same k-point grid for phonons and lambdas.
If "trans"=.false., the lambdas are calculated using
previously saved DeltaVscf in "fildvscf", previously saved
dynamical matrix, and the present punch file. This allows
the use of a different (larger) k-point grid.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: el_ph_nsigma
Type: INTEGER
Default: 10
Description: The number of double-delta smearing values used in an
electron-phonon coupling calculation.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: el_ph_sigma
Type: REAL
Default: 0.02
Description: The spacing between double-delta smearing values used in
an electron-phonon coupling calculation.
+--------------------------------------------------------------------
///---
VARIABLES FOR "ELECTRON_PHONON" = 'AHC':
+--------------------------------------------------------------------
Variable: ahc_dir
Type: CHARACTER
Default: outdir // 'ahc_dir/'
Description: Directory where the output binary files are written.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: ahc_nbnd
Type: INTEGER
Status: REQUIRED
Description: Number of bands for which the electron self-energy is to be computed.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: ahc_nbndskip
Type: INTEGER
Default: 0
Description: Number of bands to exclude when computing the self-energy. Self-energy
is computed for bands with indices from "ahc_nbndskip"+1 to
"ahc_nbndskip"+"ahc_nbnd". "ahc_nbndskip"+"ahc_nbnd" cannot
exceed nbnd of the preceding SCF or NSCF calculation.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: skip_upperfan
Type: LOGICAL
Default: .false.
Description: If .true., skip calculation of the upper Fan self-energy, which
involves solving the Sternheimer equation.
+--------------------------------------------------------------------
\\\---
+--------------------------------------------------------------------
Variable: lshift_q
Type: LOGICAL
Default: .false.
Description: Use a wave-vector grid displaced by half a grid step
in each direction - meaningful only when ldisp is .true.
When this option is set, the q2r.x code cannot be used.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: zeu
Type: LOGICAL
Default: zeu="epsil"
Description: If .true. in a q=0 calculation for a non metal the
effective charges are computed from the dielectric
response. This is the default algorithm. If "epsil"=.true.
and "zeu"=.false. only the dielectric tensor is calculated.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: zue
Type: LOGICAL
Default: .false.
Description: If .true. in a q=0 calculation for a non metal the
effective charges are computed from the phonon
density responses. This is an alternative algorithm,
different from the default one (if "trans" .and. "epsil" )
The results should be the same within numerical noise.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: elop
Type: LOGICAL
Default: .false.
Description: If .true. calculate electro-optic tensor.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: fpol
Type: LOGICAL
Default: .false.
Description: If .true. calculate dynamic polarizabilities
Requires "epsil"=.true. ( experimental stage:
see example09 for calculation of methane ).
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: ldisp
Type: LOGICAL
Default: .false.
Description: If .true. the run calculates phonons for a grid of
q-points specified by "nq1", "nq2", "nq3" - for direct
calculation of the entire phonon dispersion.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: nogg
Type: LOGICAL
Default: .false.
Description: If .true. disable the "gamma_gamma" trick used to speed
up calculations at q=0 (phonon wavevector) if the sum over
the Brillouin Zone includes k=0 only. The gamma_gamma
trick exploits symmetry and acoustic sum rule to reduce
the number of linear response calculations to the strict
minimum, as it is done in code phcg.x.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: asr
Type: LOGICAL
Default: .false.
Description: Apply Acoustic Sum Rule to dynamical matrix, effective charges
Works only in conjunction with "gamma_gamma" tricks (see above)
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: ldiag
Type: LOGICAL
Default: .false.
Description: If .true. forces the diagonalization of the dynamical
matrix also when only a part of the dynamical matrix
has been calculated. It is used together with "start_irr"
and "last_irr". If all modes corresponding to a
given irreducible representation have been calculated,
the phonon frequencies of that representation are
correct. The others are zero or wrong. Use with care.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: lqdir
Type: LOGICAL
Default: .false.
Description: If .true. ph.x creates inside outdir a separate subdirectory
for each q vector. The flag is set to .true. when "ldisp"=.true.
and "fildvscf" /= ' ' or when an electron-phonon
calculation is performed. The induced potential is saved
separately for each q inside the subdirectories.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: search_sym
Type: LOGICAL
Default: .true.
Description: Set it to .false. if you want to disable the mode
symmetry analysis.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variables: nq1, nq2, nq3
Type: INTEGER
Default: 0,0,0
Description: Parameters of the Monkhorst-Pack grid (no offset) used
when @ref ldisp=.true. Same meaning as for nk1, nk2, nk3
in the input of pw.x.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variables: nk1, nk2, nk3, k1, k2, k3
Type: INTEGER
Default: 0,0,0,0,0,0
Description: When these parameters are specified the phonon program
runs a pw non-self consistent calculation with a different
k-point grid thant that used for the charge density.
This occurs even in the Gamma case.
nk1,nk2,nk3 are the parameters of the Monkhorst-Pack grid
with offset determined by k1,k2,k3.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: diagonalization
Type: CHARACTER
Default: 'david'
Description:
Diagonalization method for the non-SCF calculations.
'david' :
Davidson iterative diagonalization with overlap matrix
(default). Fast, may in some rare cases fail.
'cg' :
Conjugate-gradient-like band-by-band diagonalization.
Slower than 'david' but uses less memory and is
(a little bit) more robust.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: read_dns_bare
Type: LOGICAL
Default: .false.
Description: If .true. the PH code tries to read three files in the DFPT+U
calculation: dns_orth, dns_bare, d2ns_bare.
dns_orth and dns_bare are the first-order variations of
the occupation matrix, while d2ns_bare is the second-order
variation of the occupation matrix. These matrices are
computed only once during the DFPT+U calculation. However,
their calculation (especially of d2ns_bare) is computationally
expensive, this is why they are written to file and then can be
read (e.g. for restart) in order to save time.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: ldvscf_interpolate
Type: LOGICAL
Default: .false.
Description: If .true., use Fourier interpolation of phonon potential
to compute the induced part of phonon potential at each
q point. Results of a dvscf_q2r.x run is needed.
Requires "trans" = .false..
+--------------------------------------------------------------------
///---
OPTIONAL VARIABLES FOR DVSCF INTERPOLATION:
+--------------------------------------------------------------------
Variable: wpot_dir
Type: CHARACTER
Default: outdir // 'w_pot/'
Description: Directory where the w_pot binary files are written.
Must be the same with wpot_dir used in dvscf_q2r.x.
The real space potential files are stored in wpot_dir
with names ${prefix}.wpot.irc${irc}//"1".
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: do_long_range
Type: LOGICAL
Default: .false.
Description: If .true., add the long-range part of the potential
to the Fourier interpolated potential as in:
S. Ponce et al, J. Chem. Phys. 143, 102813 (2015).
Reads dielectric matrix and Born effective charges from
the ${wpot_dir}/tensors.dat file, written in dvscf_q2r.x.
Currently, only the dipole (Frohlich) part is implemented.
The quadrupole part is not implemented.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: do_charge_neutral
Type: LOGICAL
Default: .false.
Description: If .true., impose charge neutrality on the Born effective
charges. Used only if "do_long_range" = .true..
+--------------------------------------------------------------------
\\\---
///---
SPECIFICATION OF IRREDUCIBLE REPRESENTATION
+--------------------------------------------------------------------
Variable: start_irr
Type: INTEGER
Default: 1
See: last_irr
Description: Perform calculations only from "start_irr" to "last_irr"
irreducible representations.
IMPORTANT:
* "start_irr" must be <= 3*nat
* do not specify "nat_todo" together with
"start_irr", "last_irr"
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: last_irr
Type: INTEGER
Default: 3*nat
See: start_irr
Description: Perform calculations only from "start_irr" to "last_irr"
irreducible representations.
IMPORTANT:
* "start_irr" must be <= 3*nat
* do not specify "nat_todo" together with
"start_irr", "last_irr"
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: nat_todo
Type: INTEGER
Default: 0, i.e. displace all atoms
Description: Choose the subset of atoms to be used in the linear response
calculation: "nat_todo" atoms, specified in input (see below)
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:
* "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
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: modenum
Type: INTEGER
Default: 0
Description: 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.
+--------------------------------------------------------------------
\\\---
///---
Q-POINT SPECIFICATION
+--------------------------------------------------------------------
Variable: start_q
Type: INTEGER
Default: 1
See: last_q
Description: Used only when ldisp=.true..
Computes only the q points from "start_q" to "last_q".
IMPORTANT:
* "start_q" must be <= "nqs" (number of q points found)
* do not specify "nat_todo" together with
"start_q", "last_q"
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: last_q
Type: INTEGER
Default: number of q points
See: start_q
Description: Used only when "ldisp"=.true..
Computes only the q points from "start_q" to "last_q".
IMPORTANT
* "last_q" must be <= "nqs" (number of q points)
* do not specify "nat_todo" together with
"start_q", "last_q"
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: dvscf_star
Type: STRUCTURE
Default: disabled
Description: It contains the following components:
dvscf_star%open (logical, default: .false.)
dvscf_star%dir (character, default: outdir//"Rotated_DVSCF" or the
ESPRESSO_FILDVSCF_DIR environment variable)
dvscf_star%ext (character, default: "dvscf") the extension to use
for the name of the output files, see below
dvscf_star%basis (character, default: "cartesian") the basis on which
the rotated dvscf will be saved
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.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: drho_star
Type: STRUCTURE
See: dvscf_star
Default: disabled
Description: It contains the following components:
drho_star%open (logical, default: .false.)
drho_star%dir (character, default: outdir//"Rotated_DRHO" or the
ESPRESSO_FILDRHO_DIR environment variable)
drho_star%ext (character, default: "drho") the extension to use
for the name of the output files, see below
drho_star%basis (character, default: "modes") the basis on which
the rotated drho will be saved
drho_star%pat (logical, default: true) save an optional file with the
displacement patterns and q vector for each drho file
Like "dvscf_star", but for the perturbation of the charge density.
Notice that the defaults are different.
+--------------------------------------------------------------------
\\\---
===END OF NAMELIST======================================================
________________________________________________________________________
* IF ldisp != .true. and qplot != .true. :
========================================================================
Line of input:
xq(1) xq(2) xq(3)
DESCRIPTION OF ITEMS:
+--------------------------------------------------------------------
Variables: xq(1) xq(2) xq(3)
Type: REAL
Description: The phonon wavevector, in units of 2pi/a0
(a0 = lattice parameter).
Not used if "ldisp"=.true. or "qplot"=.true.
+--------------------------------------------------------------------
===End of line-of-input=================================================
* ELSE IF qplot == .true. :
SPECIFICATION OF Q POINTS WHEN "QPLOT" == .TRUE.
========================================================================
CARD:
/////////////////////////////////////////
// Syntax: //
/////////////////////////////////////////
nqs
xq1(1) xq2(1) xq3(1) nq(1)
xq1(2) xq2(2) xq3(2) nq(2)
. . .
xq1(nqs) xq2(nqs) xq3(nqs) nq(nqs)
/////////////////////////////////////////
DESCRIPTION OF ITEMS:
+--------------------------------------------------------------------
Variable: nqs
Type: INTEGER
Description: Number of q points in the list. Used only if "qplot"=.true.
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variables: xq1, xq2, xq3
Type: REAL
Description: 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)
+--------------------------------------------------------------------
+--------------------------------------------------------------------
Variable: nq
Type: INTEGER
Description: The weight of the q-point; the meaning of nq depends
on the flags q2d and q_in_band_form.
+--------------------------------------------------------------------
===END OF CARD==========================================================
ENDIF
________________________________________________________________________
________________________________________________________________________
* IF nat_todo was specified :
========================================================================
Line of input:
atom(1) atom(2) ... atom(nat_todo)
DESCRIPTION OF ITEMS:
+--------------------------------------------------------------------
Variables: atom(1) atom(2) ... atom(nat_todo)
Type: INTEGER
Description: Contains the list of indices of atoms used in the
calculation if "nat_todo" is specified.
+--------------------------------------------------------------------
===End of line-of-input=================================================
ENDIF
________________________________________________________________________
:::: ADDITIONAL INFORMATION
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 "start_irr", "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 "start_irr"=0, "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, "start_irr" and
"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, "start_irr", or "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.
This file has been created by helpdoc utility on Wed Dec 02 08:04:43 CET 2020
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