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

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

Program: turbo_davidson.x / turboTDDFPT / Quantum Espresso (version: 6.6)
------------------------------------------------------------------------


    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_dav
  ...
/



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

   THIS NAMELIST IS ALWAYS NEEDED !
   
   +--------------------------------------------------------------------
   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:       max_seconds
   
   Type:           REAL
   Default:        1.D+7, or 150 days, i.e. no time limit
   Description:    jobs stops after "max_seconds" CPU time. Use this option
                   in conjunction with option "restart" if you need to
                   split a job too long to complete into shorter jobs that
                   fit into your batch queues.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       restart
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true., turbo_davidson.x will attempt to restart
                   from a previous interrupted calculation if "max_seconds"
                   was specified.
                   Beware, if set to .false. turbo_davidson.x will OVERWRITE any
                   previous runs.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   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_dav

   +--------------------------------------------------------------------
   Variable:       num_eign
   
   Type:           INTEGER
   Default:        1
   Description:    Number of eigenstates to be calculated.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       num_init
   
   Type:           INTEGER
   Default:        2
   Description:    Number of trial vectors. Usually it is twice as large as
                   the number of eigenstates to be calculated (see "num_eign").
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       if_random_init
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true. trial vectors are chosen randomly, otherwise
                   they are guessed from the ground-state calculation.
                   If "p_nbnd_occ" * "p_nbnd_virt" < "num_init", this term
                   is forced to be .true. The usage of random trial vectors should
                   cause only a slower convergence, and do not affect the final results.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       num_basis_max
   
   Type:           INTEGER
   Default:        20
   Description:    Maximum number of basis vectors allowed in the subspace.
                   When this number is reached, a discharging routine is called.
                   The memory requirement of the Davidson algorithm is mainly
                   determined by this variable (an estimation of the memory
                   is reported at the beginning of the run).
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       residue_conv_thr
   
   Type:           REAL
   Default:        1.0E-4
   Description:    Threshold for the convergence. When the square of the
                   residue is smaller than this value, the convergence
                   is achieved.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       precondition
   
   Type:           LOGICAL
   Default:        .true.
   Description:    If set to .true. a precondition is used. At this moment,
                   one sees no reason why not to use the precondition.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       single_pole
   
   Type:           LOGICAL
   Default:        .false.
   Description:    A slightly better way to set the initial trial vectors,
                   but the improvement is really small. Currently this flag
                   can be used only with LDA/PBE + NC PPs. So do not use
                   it unless it is really necessary.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       if_dft_spectrum
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true. the independent particle approximation
                   is used, i.e. the Hartree and exchange-correlation response
                   contributions are neglected.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       reference
   
   Type:           REAL
   Default:        0.0d0
   Description:    Reference energy in units of Ry. This variable is used
                   to constrain the Davidson algorithm to converge the eigenstates
                   having the energy closest to the reference energy. In this way
                   one can calculate less eigenstates at once, and to perform multiple
                   calculations with different reference energies (the post-processing
                   code tddfpt_calculate_spectrum.x can be used for this purpose).
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       broadening
   
   Type:           REAL
   Default:        0.005d0
   Description:    Lorentzian broadening (Ry) to broaden the absorption spectrum.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       start
   
   Type:           REAL
   Default:        0.0d0
   Description:    The lower limit of the energy (Ry) scale for the spectrum calculation.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       finish
   
   Type:           REAL
   Default:        1.0d0
   Description:    The upper limit of the energy (Ry) scale for the spectrum calculation.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       step
   
   Type:           REAL
   Default:        0.001d0
   Description:    Energy step (Ry) for the spectrum calculation.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       p_nbnd_occ
   
   Type:           INTEGER
   Default:        10
   Description:    Number of occupied states selected from the total number
                   of occupied states computed by PWscf. This variable is
                   useful if there are too many occupied states but your
                   are interested in only some of them.
                   In priciple this variable and "p_nbnd_virt" affect only
                   the interpretation of the eigenstates, but do not effect
                   their energy and the final absorption spectrum.
                   Make sure that min(p_nbnd_occ,nbnd_occ)*min(p_nbnd_virt,nbnd_virt)
                   is lager than the number of initial vectors ("num_init"),
                   so you will not end up using random trial vectors which would
                   slow down the convergence.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       p_nbnd_virt
   
   Type:           INTEGER
   Default:        10
   Description:    Number of empty states selected from the total number
                   of empty states computed by PWscf. This variable is
                   useful if there are too many empty states but your
                   are interested in only some of them.
                   In priciple this variable and "p_nbnd_occ" affect only
                   the interpretation of the eigenstates, but do not effect
                   their energy and the final absorption spectrum.
                   Make sure that min(p_nbnd_occ,nbnd_occ)*min(p_nbnd_virt,nbnd_virt)
                   is lager than the number of initial vectors ("num_init"),
                   so you will not end up using random trial vectors which would
                   slow down the convergence.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       poor_of_ram
   
   Type:           LOGICAL
   Default:        .false.
   Description:    Use this variable if you do not have enough RAM (only USPP),
                   i.e. set it to .true. When this variable is set to .false.,
                   you double the memory used for the USPP calculation, but you
                   increase a speed of the calculation by getting rid of
                   applying many times of s_psi and cal_bec in the
                   calculation, which takes a lot of time (sometimes more than
                   a half of the whole calculation) when the size of the
                   subspace is more than 100.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       poor_of_ram2
   
   Type:           LOGICAL
   Default:        .false.
   Description:    Use this variable if you do not have enough RAM (NCPP and USPP),
                   i.e. set it to .true. When this variable is set to .false.,
                   you double the memory used for the calculation, but you
                   increase a speed of the calculation by storing D_ and C_
                   basis: the calculation will be speeded up a lot when
                   one is calculating many transitions at the same time.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       max_iter
   
   Type:           INTEGER
   Default:        100
   Description:    Maximum number of Davidson iterations allowed. When the
                   number of iterations arrives this number, the calculation
                   will stop even if the convergence has not been achieved.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   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:       pseudo_hermitian
   
   Type:           LOGICAL
   Default:        .true.
   Description:    When set to .true. the pseudo-Hermitian Lanczos
                   algorithm is used. When set to .false. the
                   non-Hermitian Lanczos biorthogonalization algorithm
                   is used (which is two times slower).
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ltammd
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true. the Tamm-Dancoff approximation is used
                   in constructing the Liouvillian.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       lplot_drho
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true. the turbo_davidson.x code will write
                   files for each eigenstate "drho-of-eign-$i" which are
                   needed to plot the response charge-density at each resonance.
                   This implies a calculation using the pp.x post-processing
                   program with the corresponding input file which must be
                   prepared. See example "H2O-PLOTRHO".
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       d0psi_rs
   
   Type:           LOGICAL
   Default:        .false.
   Description:    When set to .true. the dipole is computed in the
                   real space. When set to .false. the dipole is
                   computed in the reciprocal space by computing [H,r].
                   Note, currently the commutator does not contain
                   a contribution for hybrids [V_EXX,r]. See also
                   the variable "lshift_d0psi".
                   Important: Treatment of the dipole in the real space
                   is allowed only if the system is finite.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       lshift_d0psi
   
   Type:           LOGICAL
   Default:        .true.
   Description:    This variable is used only when "d0psi_rs" = .true.
                   a) If a molecule is placed in the corner of the
                   supercell, there is a discontinuity problem for the
                   position operator r, which is not periodic. By setting
                   "lshift_d0psi" = .true. the discontinuity problem is
                   solved by shifting the position operator r such that
                   it is continuous and well defined.
                   b) If a molecule is placed in the center of the supercell,
                   there is no discontinuity problem for the position operator r,
                   and thus you can set "lshift_d0psi" = .false. But if you still
                   set it to .true., this will not harm, because the position
                   operator will basically remain as it is, since it is always
                   centered wrt the center of the molecule.
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


This file has been created by helpdoc utility on Wed Dec 02 08:04:50 CET 2020
