Explanation of input files (crystalline silicon under a pulsed electric field)
&calculation calc_mode = 'GS_RT' /
This indicates that the ground state (GS) and the real time (RT) calculations are carried out sequentially in the present job. See Input variables#&calculation for detail.
&control sysname = 'Si' /
'Si' defined by
sysname = 'C2H2' will be used in the filenames of output files.
Mandatory: periodic, al, state, nelem, natom
&system iperiodic = 3 al = 10.26d0,10.26d0,10.26d0 nstate = 32 nelec = 32 nelem = 1 natom = 8 /
iperiodic = 3 indicates that three dimensional periodic boundary condition (bulk crystal) is assumed.
al = 10.26d0, 10.26d0, 10.26d0 specifies the lattice constans of the unit cell.
nstate = 32 indicates the number of Kohn-Sham orbitals to be solved.
nelec = 32 indicate the number of valence electrons in the system.
nelem = 1 and
natom = 8 indicate the number of elements and the number of atoms in the system, respectively.
See Input variables#&system for more information.
&pseudo izatom(1)=14 pseudo_file(1) = './Si_rps.dat' lloc_ps(1)=2 /
izatom(1) = 14 indicates the atomic number of the element #1.
pseudo_file(1) = 'Si_rps.dat' indicates the pseudopotential filename of element #1.
lloc_ps(1) = 2 indicate the angular momentum of the pseudopotential that will be treated as local.
&functional xc = 'PZ' /
This indicates that the adiabatic local density approximation with the Perdew-Zunger functional is used. We note that meta-GGA functionals that reasonably reproduce the band gap of various insulators may also be used in the calculation of periodic systems. See Input variables#&functional for detail.
Mandatory: dl or num_rgrid
&rgrid num_rgrid = 12,12,12 /
num_rgrid=12,12,12 specifies the number of the grids for each Cartesian direction.
See Input variables#&rgrid for more information.
This namelist provides grid spacing of k-space for periodic systems.
&kgrid num_kgrid = 4,4,4 /
&tgrid nt=3000 dt=0.16 /
dt=0.16 specifies the time step of the time evolution calculation.
nt=3000 specifies the number of time steps in the calculation.
&propagation propagator='etrs' /
propagator = 'etrs' indicates the use of enforced time-reversal symmetry propagator. See Input variables#&propagation for more information.
This namelists specify parameters related to the self-consistent field calculation.
&scf ncg = 5 nscf = 120 /
ncg = 5 is the number of conjugate-gradient iterations in solving the Kohn-Sham equation. Usually this value should be 4 or 5.
nscf = 120 is the number of scf iterations.
&emfield trans_longi = 'tr' ae_shape1 = 'Acos2' rlaser_int_wcm2_1 = 1d14 pulse_tw1 = 441.195136248d0 omega1 = 0.05696145187d0 epdir_re1 = 0.,0.,1. /
This namelist specifies the pulsed electric field applied to the system
ae_shape1 = 'Acos2' specifies the envelope of the pulsed electric field,
cos^2 envelope for the vector potential.
epdir_re1 = 0.,0.,1. specify the real part of the unit polarization vector of the pulsed electric field.
Specifying only the real part, it describes a linearly polarized pulse.
laser_int_wcm2_1 = 1d14 specifies the maximum intensity of the applied electric field in unit of W/cm^2.
omega1=0.05696145187d0 specifies the average photon energy (frequency multiplied with hbar).
pulse_tw1=441.195136248d0 specifies the pulse duration.
Note that it is not the FWHM but a full duration of the cos^2 envelope.
trans_longi = 'tr' specifies the treatment of the polarization in the time evolution calculation, 'tr' indicating transverse.
See Input variables#&emfield for detail.
Mandatory: atomic_coor or atomic_red_coor (they may be provided as a separate file)
&atomic_red_coor 'Si' .0 .0 .0 1 'Si' .25 .25 .25 1 'Si' .5 .0 .5 1 'Si' .0 .5 .5 1 'Si' .5 .5 .0 1 'Si' .75 .25 .75 1 'Si' .25 .75 .75 1 'Si' .75 .75 .25 1 /
Cartesian coordinates of atoms are specified in a reduced coordinate system. First column indicates the element, next three columns specify reduced Cartesian coordinates of the atoms, and the last column labels the element.