# Crystalline silicon calculation of the GW corrections.
# Using analytic continuation for Sigma
# Dataset 1:  ground state calculation for 6 k-points in IBZ
# Dataset 2:  calculation of the screening for imaginary freqs (20 purely imaginary)
# Dataset 3:  calculation of the Self-Energy matrix elements with Analytic Continuation
# Dataset 4:  calculation of the Self-Energy matrix elements with Analytic Continuation and low-rank approximation
#

ndtset      4
gwpara      2
gwcalctyp   1

ecut      12.0
#ecutwfn    5.0
ecutwfn    12.0
ecutsigx   3.0
ecuteps    3.0

# Definition of parameters for the calculation of the KSS file
nband1      55       # Number of (occ and empty) bands to be computed
nbdbuf1     5
tolwfr1     1.0d-10

# Calculation of the screening (epsilon^-1 matrix) with spectral method
optdriver2  3        # Screening calculation
getwfk2     1
symchi2     1
awtr2       1
inclvkb2    0
nband2      25
nfreqim2    20

# Calculation of the Self-Energy matrix elements (GW corrections)
optdriver3    4        # Self-Energy calculation
getwfk3       1
getscr3       2
nband3       25
nomegasi3    10        # No. of points for \Sigma(i\omega) sampled along the imaginary axis
omegasimax3  40.0 eV 

# Calculation of the Self-Energy matrix elements (GW corrections)
optdriver4    4        # Self-Energy calculation
getwfk4       1
getscr4       2
nband4       25
nomegasi4    10        # No. of points for \Sigma(i\omega) sampled along the imaginary axis
omegasimax4  40.0 eV 

gwaclowrank4 30        # Triggers the low-rank approximation with 30 eigenvectors (out of nwpeps=59)


nkptgw  2
kptgw
    0.00000000E+00  0.00000000E+00  0.00000000E+00
    5.00000000E-01  5.00000000E-01  0.00000000E+00

bdgw
    1  7    # Enclose all the degenerate states.
    1  7    # Enclose all the degenerate states.


# Data common to the three different datasets
# Definition of the unit cell: fcc
acell  3*10.217
rprim  0.0  0.5  0.5   # FCC primitive vectors (to be scaled by acell)
       0.5  0.0  0.5
       0.5  0.5  0.0

# Definition of the atom types
ntypat  1
znucl 14

# Definition of the atoms
natom 2
typat  1 1
xred
      0.0  0.0  0.0
      0.25 0.25 0.25

# Definition of the k-point grid
ngkpt   2 2 2
nshiftk 4
shiftk
        0.0 0.0 0.0
        0.0 0.5 0.5
        0.5 0.0 0.5
        0.5 0.5 0.0

istwfk  *1         # This is mandatory in all the GW steps.

# Definition of the SCF procedure
nstep   500       # Maximal number of SCF cycles
diemac  12.0

 pp_dirpath "$ABI_PSPDIR"
 pseudos "14si.psp"

#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test = 
#%%   t32.out, tolnlines = 15, tolabs = 1.100e-03, tolrel = 3.000e-01
#%% [paral_info]
#%% max_nprocs = 8
#%% [extra_info]
#%% authors = F. Bruneval
#%% keywords = NC, GW
#%% description = 
#%%   Silicon
#%%   One-shot GW with analytic continuation of Sigma(iw)
#%%   convolution is performed on the imaginary axis = \int dz G(iw+iz) W(iz)
#%%   low-rank approximation is used in the last dataset
#%%<END TEST_INFO>