*** FILE AUTOMATICALLY CREATED: DO NOT EDIT, CHANGES WILL BE LOST ***

------------------------------------------------------------------------
INPUT FILE DESCRIPTION

Program: turbo_lanczos.x / turboTDDFPT / Quantum Espresso
------------------------------------------------------------------------


    Input data format: { } = optional, [ ] = it depends.

All quantities whose dimensions are not explicitly specified are in
RYDBERG ATOMIC UNITS

BEWARE: TABS, DOS <CR><LF> CHARACTERS ARE POTENTIAL SOURCES OF TROUBLE

Comment lines in namelists can be introduced by a "!", exactly as in
fortran code. Comments lines in ``cards'' can be introduced by
either a "!" or a "#" character in the first position of a line.

Structure of the input data:
===============================================================================

&lr_input
  ...
/

&lr_control
  ...
/

[ &lr_post
  ...
 / ]



========================================================================
NAMELIST: &lr_input

   THIS NAMELIST IS ALWAYS NEEDED !
   
   +--------------------------------------------------------------------
   Variable:       title
   
   Type:           CHARACTER
   Description:    A string describing the job.
   Status:         OPTIONAL
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       prefix
   
   Type:           CHARACTER
   Default:        'pwscf'
   Description:    Sets the prefix for generated and read files. The files
                   generated by the ground state pw.x run should have this
                   same prefix.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       outdir
   
   Type:           CHARACTER
   Default:        './'
   Description:    The directory that contains the run critical files, which
                   include the files generated by ground state pw.x run.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       wfcdir
   
   Type:           CHARACTER
   Default:        './'
   Description:    The directory that contains the run critical files, which
                   include the files generated by ground state pw.x run.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       restart
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true., turbo_lanczos.x will attempt to restart
                   from a previous interrupted calculation. (see restart_step
                   variable).
                   
                   Beware, if set to .false. turbo_lanczos.x will OVERWRITE any
                   previous runs.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       restart
   
   Type:           INTEGER
   Default:        itermax
   Description:    The code writes restart files every restart step iterations.
                   Restart files are automatically written at the end of
                   itermax Lanczos steps.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       lr_verbosity
   
   Type:           INTEGER
   Default:        1
   Description:    This integer variable controls the amount of information
                   written to standard output.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       disk_io
   
   Type:           CHARACTER
   Default:        'default'
   Description:    Fine control of disk usage. Currently only 'reduced' is
                   supported where no restart files are written, apart from
                   the 'default' mode.
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


========================================================================
NAMELIST: &lr_control

   +--------------------------------------------------------------------
   Variable:       itermax
   
   Type:           INTEGER
   Default:        500
   Description:    Number of iterations to be performed.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ipol
   
   Type:           INTEGER
   Default:        1
   Description:    An integer variable that determines which element of the
                   dynamical polarizability will be computed:
                   1 -> alpha_xx(omega), 2 -> alpha_yy(omega), and
                   3 -> alpha_zz(omega). When set to 4, three Lanczos chains
                   are sequentially performed and the full polarizability
                   tensor and the absorption coefficient are computed.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       nipol
   
   Type:           INTEGER
   Default:        1 if ipol < 4;
                   3 if ipol=4
   Description:    Determines the number of zeta coefficients to be calculated
                   for a given polarization direction.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ltammd
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true. the Tamm-Dancoff approximation is used
                   in constructing the Liouvillian.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       no_hxc
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true. the change in the internal field
                   (Hartree and exchange-correlation) is ignored in the
                   calculation, resulting in the independent electron
                   approximation.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ecutfock
   
   Type:           REAL
   Default:        ecutrho
   Description:    kinetic energy cutoff (Ry) for the exact exchange operator in
                   EXX type calculations. By default this is the same as ecutrho
                   but in some EXX calculations significant speed-up can be found
                   by reducing ecutfock, at the expense of some loss in accuracy.
                   Currently only implemented for the optimized gamma point only
                   calculations.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       charge_response
   
   Type:           INTEGER
   Default:        0
   Description:    When set to 1, the code computes the response of the charge
                   density and writes it into a file format determined by the
                   variable plot type. Setting charge response to 1 makes the
                   presence of the card lr post mandatory.
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


========================================================================
NAMELIST: &lr_post

   +--------------------------------------------------------------------
   Variable:       omeg
   
   Type:           REAL
   Default:        0.0
   Description:    The response of the charge density is calculated for this
                   transition energy (in Rydberg units)
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       epsil
   
   Type:           REAL
   Default:        0.0
   Description:    The broadening/damping term (in Rydberg units).
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       beta_gamma_z_prefix
   
   Type:           CHARACTER
   Default:        'pwscf'
   Description:    The prefix of the file where the beta gamma zeta coefficients
                   from the first calculation can be set manually using this
                   parameter. The file outdir/beta gamma z prefix.beta gamma z.x
                   (where x=1-3) must exist.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       w_T_npol
   
   Type:           INTEGER
   Default:        1
   Description:    Number of polarization directions considered in the previous
                   calculation. It must be set to 3 if in the previous calculation
                    ipol=4, it must be set to 1 otherwise.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       plot_type
   
   Type:           INTEGER
   Default:        1
   Description:    An integer variable that determines the format of the file
                   containing the charge density response. 1: A file containing
                   the x y z grid coordinates and the corre- sponding value of
                   the density is produced 2: The density response is written
                   in Xcrysden format 3: The density response is written in
                   the gaussian cube format.
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


