View source for Explanations for C2H2 rt pulse input files

== required and recommended variables ==

=== &unit ===

Mandatory: none

 &units
   unit_length='Angstrom'
   unit_energy='eV'
   unit_time='fs'
 /

This namelist specifies the unit system used in the "input" file. 
If you do not specify the units for some physical quantities, atomic unit will be used for those quantities. 

For isolated systems (specified by <code>iperiodic = 0</code> in <code>&system</code>), the units of output is basically Angstrom/eV/fs at the present.

=== &calculation ===

Mandatory: calc_mode

 &calculation
   calc_mode = 'RT'
 /

The variable <code>calc_mode</code> should be one of <code>'GS'</code>, <code>'RT'</code>, and <code>'GS-RT'</code>. 
Note that the ground state (<code>'GS'</code>) and real time (<code>'RT'</code>) calculations should be done separately and sequentially for isolated systems (specified by <code>iperiodic = 0</code> in <code>&system</code>). 
For periodic systems (specified by <code>iperiodic = 3</code> in <code>&system</code>), both ground state and real time calculations can also be carried out as a single task (<code>calc_mode = 'GS_RT'</code>).

=== &control ===

Mandatory: none

 &control
   sysname = 'C2H2'
 /

'C2H2' defined by <code>surname = 'C2H2'</code> will be used in the filenames of output files.

=== &system ===

Mandatory: iperiodic, al, nstate, nelem, natom

 &system
   iperiodic = 0
   al = 16d0, 16d0, 16d0
   nstate = 5
   nelem = 2
   natom = 4
   nelec = 10
 /

<code>iperiodic = 0</code> indicates that isolated boundary condition is assumed. 
<code>al = 16d0, 16d0, 16d0</code> specifies the lengths of three sides of a rectangular parallelepiped where the grid points are prepared. 
<code>nstate = 8</code> indicates the number of Kohn-Sham orbitals to be solved. 
<code>nelec = 10</code> indicate the number of valence electrons in the system.
<code>nelem = 2</code> and <code>natom = 4</code> indicate the number of elements and the number of atoms in the system, respectively.

=== &pseudo ===

Mandatory: pseudo_file, iZatom

 &pseudo
   iZatom(1)=6
   iZatom(2)=1
   pseudo_file(1)='C_rps.dat'
   pseudo_file(2)='H_rps.dat'
   Lmax_ps(1)=1
   Lmax_ps(2)=0
   Lloc_ps(1)=1
   Lloc_ps(2)=0
 /

Information on pseudopotentials. 
<code>iZatom(1) = 6</code> indicates the atomic number of the element 1.
<code>pseudo_file(1) = 'C_rps.dat'</code> indicates the filename of the pseudopotential of element 1. 
<code>Lmax_ps(1) = 1</code> and <code>Lloc_ps(1) = 1</code> indicate the maximum angular momentum of the pseudopotential projector and the angular momentum of the pseudopotential that will be treated as local, respectively. 

=== &tgrid ===

Mandatory: dt, Nt

  &tgrid
   dt=1.25d-3
   Nt=4800
  /

<code>dt=1.25d-3</code> specifies the time step of the time evolution calculations.
<code>Nt=4800</code> specifies the number of time steps in the calculation.

=== &emfield ===

Mandatory: ae_shape1, epdir_re1, {rlaser_int1 or amplitude1}, omega1, pulse_tw1, phi_cep1

 &emfield
   ae_shape1 = 'Ecos2'
   epdir_re1 = 0.d0,0.d0,1.d0
   rlaser_int1 = 1.d8
   omega1=9.26d0
   pulse_tw1=6.d0
   phi_cep1=0.75d0
 /

<code>ae_shape1 = 'Ecos2'</code> specifies the pulse shape of the electric field, having cos-square envelope.
<code>epdir_re1 = 0.d0,0.d0,1.d0</code> specifies the unit vector of polarization direction. 
Specifying real part of the polarization vector by 'epdir_re1', linear polarization is assumed. 
Using both real ('epdir_re1') and imaginary ('epdir_im1') parts of the polarization vector, circularly (and general ellipsoidary) polarized pulses may also be described. 
<code>laser_int1 = 1.d8</code> specifies maximum intensity of the applied electric field in unit of W/cm^2.
<code>omega1=9.26d0</code> specifies photon energy (frequency multiplied with hbar).
<code>pulse_tw1=6.d0</code> specifies the pulse duration.
Note that it is not FWHM but a full duration of the sin-square envelope.
<code>phi_cep1=0.75d0</code> specifies the carrier envelope phase of the pulse.
Note that 'phi_cep' must be 0.75 (or 0.25) if one employs 'Ecos2' pulse shape, since otherwise the time integral of the electric field does not vanish.

It is possible to use two pulses simultaneously to simulate pump-probe experiments, adding information for two pulses. 
The time delay can be specified using the variable 't1_t2'.

=== &atomic_coor ===

Mandatory: none

 &atomic_coor
 'C'    0.000000    0.000000    0.599672  1
 'H'    0.000000    0.000000    1.662257  2
 'C'    0.000000    0.000000   -0.599672  1
 'H'    0.000000    0.000000   -1.662257  2
 /

List of atomic coordinates. Last column corresponds to kinds of elements.

== additional options ==

=== &parallel ===

Mandatory: none

 &parallel
   nproc_ob = 1
   nproc_domain = 1,1,1
   nproc_domain_s = 1,1,1
 /

Followings are explanation of each variable.
* <code>nproc_ob</code>: Number of MPI parallelization for orbitals that related to the wavefunction calculation.
* <code>nproc_domain(3)'</code>: Number of MPI parallelization for each direction in real-space that related to the wavefunction calculation.
* <code>nproc_domain_s(3)'</code>: Number of MPI parallelization for each direction in real-space that related to the electron density calculation.

Defaults are <code>0</code> for <code>nproc_ob</code>, <code>(0/0/0)</code> for <code>nproc_domain</code>, and <code>(0/0/0)</code> for <code>nproc_domain_s</code>. If users use the defauls, automatic proccess assignment is done. Users can also specify <code>nproc_ob</code>, <code>nproc_domain</code>, and <code>nproc_domain_s</code> manually. In that case, followings must be satisfied.
* nproc_ob</code> * <code>nproc_domain(1)</code> * <code>nproc_domain(2)</code>* <code>nproc_domain(3)</code>=total number of processors
* <code>nproc_domain_s(1)</code> * <code>nproc_domain_s(2)</code>* <code>nproc_domain_s(3)</code>=total number of processors
* <code>nproc_domain_s(1)</code> is a multiple of <code>nproc_domain(1)</code>
* <code>nproc_domain_s(2)</code> is a multiple of <code>nproc_domain(2)</code>
* <code>nproc_domain_s(3)</code> is a multiple of <code>nproc_domain(3)</code>

=== &hartree ===

Mandatory: none

 &hartree
   meo = 3
   num_pole_xyz = 2,2,2
 /

<code>meo</code> specifies the order of multipole expansion of electron density that is used to prepare boundary condition for the Hartree potential. 
* <code>meo=1</code>: Single pole is set.
* <code>meo=2</code>: Multipoles are set to the position of atoms. 
* <code>meo=3</code>: Multipoles are set to the center of mass of electrons in cuboids.
<code>num_pole_xyz(3)</code> are number of multipoles when <code>meo</code> is <code>3</code>. A default for <code>meo</code> is <code>3</code>, and defaults for <code>num_pole_xyz</code> are <code>(0,0,0)</code>. When default is set, number of multipoles is calculated automatically.

=== &analysis ===

Mandatory: none

 &analysis
   out_dns_rt = 'y'
   out_elf_rt = 'y'
   out_estatic_rt = 'y'
 /

These namelists specify the output files. If <code>output_dns_rt</code> is <code>'y'</code>, files for electron density and difference of electron density in some time steps are generated.