problem in GW approximation

[amiri]

Daer all users
I apply the GW-correction on the graphene sheet but i have a strange letters in the part of GW-energy. Does someone knows whats is the reason of that?
my input file is as below:


# graphene sheet
# Calculation of the G_0 W_0 corrections

ndtset 3

# Dataset1: usual self-consistent ground-state calculation
prtden1 1 # Print out density
prtpot1 1 # Print out the Hartree potential
prtvxc1 1 # Print out the Hartree potential
nband1 20
nbandkss1 20 # Number of bands in KSS file (the maximum possible)
kssform1 3 # conjugate gradient algorithm

# Calculation of the dielectric matrix
optdriver2 3
getkss2 1
ecuteps2 3.0
ecutwfn2 25.0
awtr2 1
nband2 20
gw_EET2 2 # switch on energy effective technique (EET) by Berger et al. PRB 82, 041103 (2010).


# Calculation of the GW corrections
optdriver3 4
getkss3 1
getscr3 2
nband3 20
ecutwfn3 25.0
ecutsigx3 8.0
gw_EET3 2 # switch on energy effective technique (EET) by Berger et al. PRB 82, 041103 (2010).
nkptgw3 1
kptgw3 0.000 0.000 0.000
# 1/3 0.000 0.000

bdgw3 2 16
# 2 16

# GW calculation general parameters
# ppmfrq 10.0 eV
ppmodel 2 # Hybertson-Louie plasmon pole model
icutcoul 2 # => cylinder (nanowires, nanotubes)
vcutgeo 1 1 0 # along the z-axis, Beigi's approach, PRB 73, 233103
rcut 20 # radius of sphere for Coulomb potential cutoff
inclvkb 2 # When inclvkb==2 the commutator F(r1,r2) = [Vnl(r1,r2),r2] is rewritten
# in reciprocal space in a fully separable form so that the storage
# of the huge two-dimensional matrix F(G1,G2) is not needed.
# On the contrary Inclvkb==1 requires the entire F(G1,G2) matrix hence
# it is much more memory demanding and much slower for large cutoff energies.
# Hartree and xc potential is computed (which can require some
# sizeable memory space also).
gwmem 0 # gwmem governs the memory strategy during a screening and/or a sigma run.
# * gwmem = 1x , the screening matrix are read for all q-vectors and stored in the memory.
# * gwmem = 0x , the screening matrix are read just a q-vector after another.
# * gwmem = x1 , the real-space wavefunctions are stored in the memory.
# * gwmem = x0 , the real-space wavefunctions are not stored,
# but rather recalculated on-fly each abinit needs them using FFTs.
# The default is gwmem = 11, which is the fastest, but also the most memory consuming.
# When experiencing memory shortage, one should try gwmem = 0. The first digit is
# only meaningful when performing sigma calculations.
# mkmem 0 # Sets the maximum number of k points for which the ground state wavefunctions
# are kept in core memory at one time.
# This value should either be 0, in which case an out-of-core solution will be used
# A reduction of the requireed memory can be achieved by opting for an out-of-core
# solution (mkmem=0, only coded for optdriver=3) at the price of a drastic worsening
# of the performance.
gwpara 1 # => parallelisation on bands
mffmem 1
# Definition of the SCF procedure
ecut 25.0 # Maximal kinetic energy cut-off, in Hartree
nstep 120
toldfe 1e-10
diemac 2.0
iscf 7

# BZ sampling
kptopt 1 # Option for the automatic generation of k points,
nshiftk 1
shiftk 0.0 0.0 0.0 # These shifts will be the same for all grids
istwfk *1
ngkpt 2 1 1
symmorphi 0 # Use only symmorphic operations


####################################################################################
# Definition of the structure
####################################################################################
chkprim 0
chksymbreak 0
acell 4.6390262670 8.077574780 40.0000

rprim 1.0 0.0 0.0
0.0 1.0 0.0
0.0 0.0 1.0

# Definition of the atom types
ntypat 1
znucl 6
natom 4
typat 1 1 1 1
xangst

8.5905895062E+00 3.5515456535E+00 0.0000000000E+00
9.8181907544E+00 4.266591258E+00 0.0000000000E+00
8.5904597857E+00 2.1292785330E+00 0.0000000000E+00
9.8181668072E+00 1.4145377489E+00 0.0000000000E+00



and the part of my output file that include strange letters is as below:

k = 0.000 0.000 0.000
Band E0 <VxcLDA> SigX SigC(E0) Z dSigC/dE Sig(E) E-E0 E
2 -16.814 -16.076 -23.436 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
3 -15.827 -15.592 -21.572 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
4 -10.207 -12.806 -16.012 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
5 -8.910 -16.985 -21.238 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
6 -5.679 -17.455 -20.688 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
7 -5.546 -17.576 -21.264 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
8 -4.955 -13.838 -15.232 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
9 -0.908 -13.134 -7.499 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
10 0.613 -3.002 -1.144 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
11 1.378 -1.458 -0.313 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
12 1.679 -0.304 -0.089 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
13 2.478 -0.896 -0.208 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
14 2.898 -0.885 -0.335 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
15 4.364 -1.133 -0.290 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ
16 4.928 -1.249 -0.464 NaNQ NaNQ NaNQ NaNQ NaNQ NaNQ



the output file and log file are also attached to this e-mail.
Any suggestion will be appreciated.
Thanks
Peiman

[Robin]

Dear Peiman,

I did such calculation before and the attached is my input file for your reference.

Sincerely,
Guangfu Luo