# Crystalline silicon
# Calculation of the GW corrections with Spectral method for chi0 and analytic continuation for Sigma
# Dataset 1: ground state calculation and of the kss file for 16 k-points in IBZ.
# Dataset 2: calculation of the screening so to obtain the RPA correlation energy
# Dataset 3: calculation of the screening so to obtain the RPA correlation energy with numerical integration
# Dataset 3: calculation of the screening so to obtain the RPA correlation energy with extrapolar trick
# Dataset 4: calculation of the screening so to obtain the RPA correlation energy with extrapolar trick and with a long-range only Coulomb interaction
ndtset 5
gwpara 2
fftgw 31 # Use the densest FFT mesh for oscillator (compatible with symmetries)
symchi 0 # The default (symchi 0) is much better
# Parameters for the calculation of the KSS file
nband1 35
nbdbuf1 5
# Calculation of the screening and of the RPA correlation energy
optdriver2 3 # Screening calculation
gwrpacorr2 1 # calculation of the RPA correlation energy with exact integration over the coupling constant
gwcalctyp2 1 # Gauss-Legendre frequency mesh on the imaginary axis
nfreqim2 6 # No. of points along the imaginary axis for chi0
getwfk2 1 # Obtain the KSS file from previous dataset
awtr2 1 # Take advantage of time reversal symmetry to halve CPU time.
nband2 30 # Bands to be used in the chi0 calculation
ecuteps2 5.0 # Cut-off energy of the planewave set to represent the dielectric matrix
inclvkb2 0 # Do not include [Vnl, r] for q-->0
# Calculation of the screening and of the RPA correlation energy
optdriver3 3 # Screening calculation
gwrpacorr3 8 # calculation of the RPA correlation energy with numerical integration over the coupling constant
# using 8 Gauss-Legendre points
gwcalctyp3 1 # Gauss-Legendre frequency mesh on the imaginary axis
nfreqim3 6 # No. of points along the imaginary axis for chi0
getwfk3 1 # Obtain the KSS file from previous dataset
awtr3 1 # Take advantage of time reversal symmetry to halve CPU time.
nband3 30 # Bands to be used in the chi0 calculation
ecuteps3 5.0 # Cut-off energy of the planewave set to represent the dielectric matrix
inclvkb3 0
# Calculation of the screening and of the RPA correlation energy
optdriver4 3 # Screening calculation
gwrpacorr4 1 # calculation of the RPA correlation energy with exact integration over the coupling constant
gwcalctyp4 1 # Gauss-Legendre frequency mesh on the imaginary axis
nfreqim4 6 # No. of points along the imaginary axis for chi0
getwfk4 1 # Obtain the KSS file from previous dataset
awtr4 1 # Take advantage of time reversal symmetry to halve CPU time.
nband4 30 # Bands to be used in the chi0 calculation
ecuteps4 5.0 # Cut-off energy of the planewave set to represent the dielectric matrix
inclvkb4 0
gwcomp4 1 # Extrapolar trick to accelerate convergence vs. empty bands
gwencomp4 1.00
# Calculation of the screening and of the RPA correlation energy
optdriver5 3 # Screening calculation
gwrpacorr5 1 # calculation of the RPA correlation energy with exact integration over the coupling constant
gwcalctyp5 1 # Gauss-Legendre frequency mesh on the imaginary axis
nfreqim5 6 # No. of points along the imaginary axis for chi0
getwfk5 1 # Obtain the KSS file from previous dataset
awtr5 1 # Take advantage of time reversal symmetry to halve CPU time.
nband5 30 # Bands to be used in the chi0 calculation
ecuteps5 5.0 # Cut-off energy of the planewave set to represent the dielectric matrix
inclvkb5 0
gwcomp5 1 # Extrapolar trick to accelerate convergence vs. empty bands
gwencomp5 1.00
icutcoul5 4 # long-range only electron-electron interaction
rcut5 1.00
###############################################
# Data common to the different datasets
###############################################
# Definition of the unit cell: fcc
acell 3*10.217 # This is equivalent to 10.217 10.217 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 # 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
kptopt 1 # Option for the automatic generation of k points,
ngkpt 2 2 2
nshiftk 1
shiftk 0.0 0.0 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
ecutwfn 8.0
# Definition of the SCF procedure
nstep 50 # Maximal number of SCF cycles
tolwfr 1.0d-10 # Will stop when this tolerance is achieved on total energy
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.
## After modifying the following section, one might need to regenerate the pickle database with runtests.py -r
#%%
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test =
#%% t19.out, tolnlines = 18, tolabs = 1.1e-3, tolrel = 3.0e-3, fld_options = -medium
#%% psp_files = 14si.pspnc
#%% [paral_info]
#%% max_nprocs = 3
#%% [extra_info]
#%% authors = F. Bruneval
#%% keywords = GW, FAILS_IFMPI
#%% description =
#%% RPA correlation energy calculation in Si:
#%% using exact or numerication integration over the coupling constant, using extrapolar trick or not,
#%% using the full or long-range only Coulomb interaction
#%% topics = RPACorrEn
#%%