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k-points' option in response function calculations

From: yunhee.chang@kriss.re.kr
To: forum@abinit.org
Subject: k-points' option in response function calculations
Date: Thu, 13 Jul 2006 10:26:04 +0200

Dear Abinit users,

I have an question about the k-points' sampling option in response function
calculations.
When I calculate the phonon band in q\=o,
I used kptopt 0 and I defined the kpoints explicitly by myself using kptopt 0
options,
at that time there is an error message like below.

------------------------------------------------------------------
getkgrid : BUG -
The argument nkpt= 16, does not match
the number of k points generated by kptopt, kptrlatt, shiftk,
and the eventual symmetries, that is, nkpt= 2.
However, note that it might due to the user,
if nkpt is explicitely defined in the input file.
In this case, please check your input file.
Action : contact ABINIT group.
-------------------------------------------------------------------

My problem in my input variables is the reciprocal primitive cell is oblique,
so I cannot use the kpoint grid directly just ngkpt something like that.
I need some other options to make kpoints' grid.

Would you give me any comments?

My input files are below.

=====================================================================
# In/Si(111) surface phonon frequencies : 4x1 5BL

ndtset 8
#Set 1 : ground state self-consistency

getwfk1 0 # Cancel default
kptopt1 0 # Automatic generation of k points, taking
# into account the symmetry
nkpt1 16
kpt1 0.000000 0.062500 0.000000
0.250000 0.062500 0.000000
0.500000 0.062500 0.000000
-0.250000 0.062500 0.000000
-0.250000 0.187500 0.000000
0.000000 0.187500 0.000000
0.250000 0.187500 0.000000
0.500000 0.187500 0.000000
0.500000 0.312500 0.000000
-0.250000 0.312500 0.000000
0.000000 0.312500 0.000000
0.250000 0.312500 0.000000
0.250000 0.437500 0.000000
0.500000 0.437500 0.000000
-0.250000 0.437500 0.000000
0.000000 0.437500 0.000000
nqpt1 0 # Cancel default
tolvrs1 1.0d-18 # SCF stopping criterion (modify default)
rfphon1 0 # Cancel default
# irdwfk1 1

#Q vectors for all datasets

#Complete set of symmetry-inequivalent qpt chosen to be commensurate
# with kpt mesh so that only one set of GS wave functions is needed.
#Generated automatically by running GS calculation with kptopt=1,
# nshift=0, shiftk=0 0 0 (to include gamma) and taking output kpt set
# file as qpt set. Set nstep=1 so only one iteration runs.

nqpt 1 # One qpt for each dataset (only 0 or 1 allowed)
# This is the default for all datasets and must
# be explicitly turned off for dataset 1.

42,0-1 Top
kptopt3 0 # Modify default to use time-reversal symmetry
nkpt3 16
kpt3 0.000000 0.062500 0.000000
0.250000 0.062500 0.000000
0.500000 0.062500 0.000000
-0.250000 0.062500 0.000000
-0.250000 0.187500 0.000000
0.000000 0.187500 0.000000
0.250000 0.187500 0.000000
0.500000 0.187500 0.000000
0.500000 0.312500 0.000000
-0.250000 0.312500 0.000000
0.000000 0.312500 0.000000
0.250000 0.312500 0.000000
0.250000 0.437500 0.000000
0.500000 0.437500 0.000000
-0.250000 0.437500 0.000000
0.000000 0.437500 0.000000
nqpt1 0 # Cancel default
rfelfd3 3 # Electric-field perturbation response only

#Sets 4-20 : Finite-wave-vector phonon calculations (defaults for all
datasets)

getwfk 1 # Use GS wave functions from dataset1
kptopt 0 # Need full k-point set for finite-Q response
rfphon 1 # Do phonon response
rfatpol 1 50 # Treat displacements of all atoms
rfdir 1 1 1 # Do all directions (symmetry will be used)
tolvrs 1.0d-8 # This default is active for sets 3-10

#######################################################################
#Common input variables
occopt 3
tsmear 0.0007

#Definition of the unit cell
acell 2.105671378027334 3.647129810786902
1.488934510353547
rprim 12.000000000000000 -6.928203230275486
0.000000000000000
0.000000000000000 2.000000000000000
0.000000000000000
0.000000000000000 0.000000000000000
40.000000000000000

#Definition of the atom types

81,3 37%

2.2344419491E+00 1.9301145068E+00 9.4199528997E+00
5.5562663125E+00 2.0152237612E-04 9.4800422240E+00
8.9147110656E+00 1.9302195388E+00 9.4734115711E+00
1.2234264538E+01 1.7634343203E-04 9.4486793015E+00

1.3360858385E+01 -5.7897733207E+00 8.6694961717E+00
3.3457482003E+00 1.2211630068E-04 8.6424914663E+00
6.6792948468E+00 1.9301577383E+00 8.6935171646E+00
1.0011974431E+01 2.0500561397E-04 8.6603137488E+00

1.3364532718E+01 -5.7897353798E+00 6.3033937985E+00
3.3433921418E+00 1.5725090939E-04 6.2859274949E+00
6.6820385888E+00 1.9301619323E+00 6.3192393493E+00
1.0019095314E+01 2.0551760684E-04 6.2983096719E+00

1.1091636040E+00 1.6095432412E-04 5.5120063250E+00
4.4596154027E+00 1.9301064036E+00 5.5081796823E+00
7.7912123640E+00 1.5095487707E-04 5.5153478391E+00
1.1136465802E+01 -5.7897659263E+00 5.5116724102E+00

1.1142728800E+00 0.0000000000E+00 3.1516396500E+00
4.4570915400E+00 1.9299772500E+00 3.1516396500E+00
7.7999101900E+00 0.0000000000E+00 3.1516396500E+00
1.1142728840E+01 -5.7899317500E+00 3.1516396500E+00

2.2285457700E+00 1.9299772500E+00 2.3637297400E+00
5.5713644200E+00 0.0000000000E+00 2.3637297400E+00
8.9141830700E+00 1.9299772500E+00 2.3637297400E+00
1.2257001720E+01 0.0000000000E+00 2.3637297400E+00

2.2285457700E+00 1.9299772500E+00 8.9821730000E-01
5.5713644200E+00 0.0000000000E+00 8.9821730000E-01
8.9141830700E+00 1.9299772500E+00 8.9821730000E-01
1.2257001720E+01 0.0000000000E+00 8.9821730000E-01

#Gives the number of band, explicitely (do not take the default)
nband 110

#Exchange-correlation functional

ixc 11 # GGA Perdew-Burke-Ernzerhof GGA functional

161,0-1 75%
0.000000 -0.437500 0.000000
nqpt1 0 # Cancel default
# ngkpt 4 16 1
# nshiftk 1
# shiftk 0.5 0.5 0.0

#kptopt 1 # Option for the automatic generation of k points, taking
#Definition of the SCF procedure
iscf 5 # Self-consistent calculation, using algorithm 5
nstep 30 # 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.
# The dielectric constant of AlAs is smaller that the
one of Si (=12).
=============================================================================

Would you give me any comments about the option of kpoint's sampling
in oblique unit cell?
Thank you very much~!

Best regards,
Yunhee Chang

k-points' option in response function calculations, yunhee . chang, 07/13/2006