Explanations for C2H2 gs input files

&unit

Mandatory: none

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

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

For isolated systems (specified by iperiodic = 0 in &system), DOS and PDOS are written by a.u. or 1/eV according to unit_energy. For other output files, the units are basically Angstrom/eV/fs at the present.

&calculation

Mandatory: calc_mode

&calculation
  calc_mode = 'GS'
/

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

&control

Mandatory: none

&control
  sysname = 'C2H2'
/

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

&parallel

Mandatory: nproc_ob, nproc_domain, nproc_domain_s

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

For isolated systems (specified by iperiodic = 0 in &system), these parameters must be set. nproc_ob = 1 indicates the number of MPI parallelization for orbitals. nproc_domain = 1,1,1 indicates the spatial division for orbitals in x,y,z directions. nproc_domain_s = 1,1,1 indicates the spatial divisions for Hartree potential in x,y,z directions.

Followings must be satisfied:

• nproc_ob * nproc_domain(1) * nproc_domain(2)* nproc_domain(3)=total number of processors
• nproc_domain_s(1) * nproc_domain_s(2)* nproc_domain_s(3)=total number of processors
• nproc_domain_s(1) is a multiple of nproc_domain(1)
• nproc_domain_s(2) is a multiple of nproc_domain(2)
• nproc_domain_s(3) is a multiple of nproc_domain(3)

&system

Mandatory: iperiodic, al, nstate, nelem, natom

 &system
  iperiodic = 0
  al = 16d0, 16d0, 16d0
  nstate = 8
  nelec = 10
  nelem = 2
  natom = 4

/

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

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

&rgrid

Mandatory: dl or num_rgrid

&rgrid
  dl = 0.25d0, 0.25d0, 0.25d0
/

dl = 0.25d0, 0.25d0, 0.25d0 specifies grid spacing in three Cartesian directions. The grid spacing can also be specified by num_rgrid that specifies the number of grid points.

&scf

Mandatory: nscf

&scf
  nscf = 150
/

nscf is number of scf iterations.

&analysis

Mandatory: none

&analysis
  out_psi = 'y'
  out_dns = 'y'
  out_dos = 'y'
  out_pdos = 'y'
  out_elf = 'y'
/

These namelists specify the output files.

&hartree

Mandatory: num_pole_xyz(1:3) if meo=3 is specified

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

meo = 3 specifies the order of multipole expansion of electron density that is used to prepare boundary condition for the Hartree potential. num_pole_xyz(1:3) are numbers of cuboids in which multipoles set for x-, y-, and z-directions.

&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.