Input File Description

Atomic mass [amu] of each atomic type.
If not specified, masses are read from data file.
         

Directory containing input, output, and scratch files;
must be the same as specified in the calculation of
the unperturbed system.
         

Prepended to input/output filenames; must be the same
used in the calculation of unperturbed system.
         

Maximum number of iterations in a scf step. If you want
more than 100, edit variable "maxter" in PH/phcom.f90
         

 Threshold for self-consistency.
         

Mixing factor (for each iteration) for updating
the scf potential:

vnew(in) = alpha_mix*vold(out) + (1-alpha_mix)*vold(in)
         

 Number of iterations used in potential mixing.
         

'debug', 'high', 'medium'   = verbose output
'low', 'default', 'minimal' = short output
         

 Reduce I/O to the strict minimum.
         

 Maximum allowed run time before the job stops smoothly.
         

 File where the dynamical matrix is written.
         

 File where the charge density responses are written.
         

File where the the potential variation is written
(for later use in electron-phonon calculation).
         

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.
         

If .true. the dielectric constant is calculated at the
RPA level with DV_xc=0.
         

If .true. the dielectric constant is calculated without
local fields, i.e. by setting DV_H=0 and DV_xc=0.
         

If .true. the phonons are computed.
If trans .and. epsil are .true. effective charges are
calculated.
         

If .true. calculate non-resonant Raman coefficients
using second-order response as in:
M. Lazzeri and F. Mauri, Phys. Rev. Lett. 90, 036401 (2003).
         

 If .true. restart from an interrupted run.
         

If .true. search in the phsave directory only the
                 quantities requested in input.
         

If .true. only the bands and other
                  initialization quantities are calculated.
                  (used for GRID parallelization)
         

 If .true. a list of q points is read from input.
         

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.
         

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.
         

If equal to '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.

If equal to 'interpolated' electron-phonon is calculated
by interpolation over the Brillouin Zone as in
M. Wierzbowska, et al. arXiv:cond-mat/0504077

For metals only, requires gaussian smearing.

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.
         

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.
         

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.
         

If .true. calculate electro-optic tensor.
         

If .true. calculate dynamic polarizabilities
Requires epsil=.true. ( experimental stage:
see example09 for calculation of methane ).
         

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.
         

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. This option MUST
BE USED if a run with ph.x is to be followed by a run
with d3.x for third-order terms calculation.
         

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.
         

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.
         

Set it to .false. if you want to disable the mode
symmetry analysis.