# Crystalline LiF: Hilbert transform for chi0(w) with nfreqre, freqremin, freqremax

ndtset 4

ngkpt     4 4 4              # Number of grid points for k-point generation
nshiftk   1
shiftk    0 0 0              # Mesh centered on gamma
kptopt    1                  # Automatic generation of k-points
istwfk    *1                 
                             

# Definition of the unit cell: fcc
#acell 3*7.6079786             # Lattice constants (in atomic units)
acell 3*7.7034756             # Lattice constants (in atomic units)

rprim 0.0 0.5 0.5             # FCC primitive vectors
      0.5 0.0 0.5             # (to be scaled by acell)
      0.5 0.5 0.0

ntypat 2                      # Number of species
znucl  3 9                    # Z number of each species
natom  2                      # Number of atoms
typat  1 2                    # Type of each atom (index in znucl)
xred   0.00    0.00    0.00   # Reduced coordinates of atom 1
       0.50   -0.50   -0.50   # Reduced coordinates of atom 2

# Definition of the plane-wave basis set
ecut    15.0                  # Kinetic energy cut-off, in Hartree
ecutwfn 15.0
ecuteps 3
prtsuscep 1

gwcalctyp    2    # CD method
spmeth       1    # Use Hilbert transform : Im chi0 --> chi0.
nomegasf   250    # Number of points for Imchi0 (should be subject of convergence tests,
                  # as the frequency step should be small enough to describe the behaviour of
                  # the delta function


# Definition of the SCF procedure
nstep 50                   # Maximum number of SCF cycles


# Step 1: determine the ground state
nband1  10                    # Number of bands
tolvrs1  1.0d-12              # Tolerance to stop SCF cycles

# Step 2: obtain the Kohn-Sham band structure and generate the WFK file
getden2    1                  # Read electronic density from step 1
iscf2     -2                  # Non self-consistent calculation
nbdbuf2    4
tolwfr2    1.0d-12            # Tolerance on wavefunctions
nband2    50                  # Number of bands for the system


# Dataset3: Screening (eps^-1) matrix
optdriver3   3
getwfk3      2
nband3       50
nfreqim3     5
nfreqre3     21
freqremin3   0 eV
freqremax3   20 eV

# Dataset4: Screening (eps^-1) matrix
optdriver4   3
getwfk4      2
nband4       50
nfreqim4     0
nfreqre4     11
freqremin4   21 eV
freqremax4   31 eV


 pp_dirpath "$ABI_PSPDIR"
 pseudos "03-Li.psp, 09-F.psp"

#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% test_chain = t37.in, t38.in, t39.in
#%% [files]
#%% files_to_test = 
#%%   t37.out, tolnlines = 20, tolabs = 2.0e-2, tolrel = 5.0e-1, fld_options = -ridiculous;
#%% [paral_info]
#%% max_nprocs = 8
#%% [extra_info]
#%% authors = M. Giantomassi
#%% keywords = NC, GW
#%% description = 
#%%   LiF. Hilbert transform for chi0. Use nfreqre and freqremin, freqremax to split 
#%%   the calculation along the real axis. The SCR files produced in dataset 3 and 4
#%%   are then merged my mrgscr in the next test.
#%%<END TEST_INFO>