# Crystalline silicon
# Calculation of the GW corrections
# Dataset 1: ground state calculation to get the density
# Dataset 2: NSCF run to produce the WFK file for 10 k-points in IBZ
# Dataset 3: calculation of the screening (epsilon^-1 matrix for W)
# Dataset 4: calculation of the Self-Energy matrix elements (GW corrections)
ndtset 4
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# Dataset 1
############
# SCF-GS run
nband1 6
tolvrs1 1.0e-10
############
# Dataset 2
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# Definition of parameters for the calculation of the WFK file
nband2 100 # Number of (occ and empty) bands to be computed
nbdbuf2 20 # Do not apply the convergence criterium to the last 20 bands (faster)
iscf2 -2
getden2 -1
tolwfr2 1.0d-12 # Will stop when this tolerance is achieved
############
# Dataset 3
############
# Calculation of the screening (epsilon^-1 matrix)
optdriver3 3 # Screening calculation
getwfk3 -1 # Obtain WFK file from previous dataset
nband3 60 # Bands to be used in the screening calculation
ecuteps3 3.6 # Cut-off energy of the planewave set to represent the dielectric matrix.
# It is important to adjust this parameter, that is usually smaller than ecut,
# and between 5 and 10 Ha..
ppmfrq3 16.7 eV # Imaginary frequency where to calculate the screening.
# It is easier (and safer) to let ABINIT compute and use the Drude plasma frequency,
# instead of selecting a value by hand. This would be done thanks to the default value ppmfrq 0.0 .
############
# Dataset 4
############
# Calculation of the Self-Energy matrix elements (GW corrections)
optdriver4 4 # Self-Energy calculation
getwfk4 -2 # Obtain WFK file from dataset 1
getscr4 -1 # Obtain SCR file from previous dataset
nband4 80 # Bands to be used in the Self-Energy calculation
ecutsigx4 8.0 # Dimension of the G sum in Sigma_x.
# ecutsigx = ecut is usually a wise choice
# (the dimension in Sigma_c is controlled by ecuteps)
nkptgw4 1 # number of k-point where to calculate the GW correction
kptgw4 # k-points in reduced coordinates
0.000 0.000 0.000
bdgw4 4 5 # calculate GW corrections for bands from 4 to 5
# Data common to the three different datasets
# Definition of the unit cell: fcc
acell 3*10.26 # Experimental lattice constants
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 # There is only one type of atom
znucl 14 # The keyword "znucl" refers to the atomic number of the
# possible type(s) of atom. The pseudopotential(s)
# mentioned in the "files" file must correspond
# to the type(s) of atom. Here, the only type is Silicon.
# Definition of the atoms
natom 2 # There are two atoms
typat 1 1 # They both are of type 1, that is, Silicon.
xred # Reduced coordinate of atoms
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 # These shifts will be the same for all grids
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 planewave basis set (at convergence 16 Rydberg 8 Hartree)
ecut 8.0 # Maximal kinetic energy cut-off, in Hartree
# Definition of the SCF procedure
nstep 20 # Maximal number of SCF cycles
diemac 12.0 # Although this is not mandatory, it is worth to
# precondition the SCF cycle. The model dielectric
# function used as the standard preconditioner
# is described in the "dielng" input variable section.
# Here, we follow the prescription for bulk silicon.
pp_dirpath "$ABI_PSPDIR"
pseudos "Pseudodojo_nc_sr_04_pbe_standard_psp8/Si.psp8"
##############################################################
# This section is used only for regression testing of ABINIT #
##############################################################
#%%
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test =
#%% tgw1_1.abo, tolnlines= 10, tolabs= 0.03, tolrel= 1.500e-01
#%% [paral_info]
#%% max_nprocs = 4
#%% [extra_info]
#%% authors = V. Olevano, F. Bruneval, M. Giantomassi
#%% keywords = GW
#%% description =
#%% Crystalline silicon
#%% Calculation of the GW corrections
#%% Dataset 1: ground state calculation to get the density
#%% Dataset 2: NSCF run to produce the WFK file for 10 k-points in IBZ
#%% Dataset 3: calculation of the screening (epsilon^-1 matrix for W)
#%% Dataset 4: calculation of the Self-Energy matrix elements (GW corrections)
#%%