ABINIT Discussion Forums

Dear Colleagues,

I am trying to calculate the phonon dispersion of the 10,10 carbon nanotube system. The structure is primitive monoclinic and I already optimized the geometry of the molecule. Currently I am trying to get a phonon band structure first using only a very coarse 2x2x2 k-point mesh which I will refine once the test calculation has been successful. But unfortunately this is not the case. Abinit is terminating after it has read in the WFK file containing the k-points of the irreducible Brillouin Zone. It seems to be missing k-points in the input file. This only happens when it attempts to compute the phonon spectrum at q-points deviating from Gamma (0/0/0). Here is the input file:

start of nano10_10phband.in

# Nanotube (10,10): computation of the phonon spectrum

ndtset 5
#Set 1 : ground state self-consistency

getwfk1 0

kptopt1 1
nqpt1 0
tolvrs1 1.0d-18
rfphon1 0
#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.

qpt2 0.00000000E+00 0.00000000E+00 0.00000000E+00
qpt3 0.00000000E+00 0.00000000E+00 0.00000000E+00
qpt4 2.50000000E-01 2.50000000E-01 2.50000000E-01
qpt5 -2.50000000E-01 2.50000000E-01 2.50000000E-01



#Set 2 : Response function calculation of d/dk wave function

iscf2 -3 # Need this non-self-consistent option for d/dk
kptopt2 2 # Modify default to use time-reversal symmetry
rfphon2 0 # Cancel default
rfelfd2 2 # Calculate d/dk wave function only
tolwfr2 1.0d-20 # Use wave function residual criterion instead
#Set 3 : Response function calculation of Q=0 phonons and electric field pert.

getddk3 2 # d/dk wave functions from last dataset
kptopt3 2 # Modify default to use time-reversal symmetry
rfelfd3 3 # Electric-field perturbation response only

#Sets 4-10 : Finite-wave-vector phonon calculations (defaults for all datasets)

getwfk 1 # Use GS wave functions from dataset1
kptopt 3 # Need full k-point set for finite-Q response
rfphon 1 # Do phonon response
rfatpol 1 40 # 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

acell 3.4388274773E+01 3.4339311781E+01 5.1182406877E+00 angstrom
angdeg 90.00000000 90.00000000 118.59085773
rprim 9.9991939667E-01 1.2696462358E-02 0.0000000000E+00
-4.8966143311E-01 8.7191265671E-01 0.0000000000E+00
6.1232339957E-17 1.0605752387E-16 1.0000000000E+00

#Definition of the atom types
ntypat 1 # There are two types of atom
znucl 6

#Definition of the atoms
natom 40
typat 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
xred

9.08671573486572E-01 4.95883996283853E-01 0.00000000000000E+00
9.49261099441318E-01 5.94035756433978E-01 4.70197740328915E-38
9.62839077132965E-01 6.42386142328436E-01 5.00000000000000E-01
9.73858314174410E-01 7.33527841546566E-01 5.00000000000000E-01
9.71154560537238E-01 7.75704229929748E-01 0.00000000000000E+00
9.49562697456474E-01 8.49637319818806E-01 2.35098870164458E-38
9.31119515174017E-01 8.81189894832726E-01 5.00000000000000E-01
8.80856602323744E-01 9.31332539571378E-01 5.00000000000000E-01
8.49276442911868E-01 9.49715655067475E-01 0.00000000000000E+00
7.75345135737553E-01 9.71188744551617E-01 0.00000000000000E+00
7.33195066693436E-01 9.73834266370185E-01 5.00000000000000E-01
6.42140238665746E-01 9.62694047271810E-01 5.00000000000000E-01
5.93850496713949E-01 9.49071461277420E-01 2.35098870164458E-38
4.95840391058973E-01 9.08491890803740E-01 0.00000000000000E+00
4.46380449980232E-01 8.81995308048743E-01 5.00000000000000E-01
3.50160983470368E-01 8.18551178013578E-01 5.00000000000000E-01
3.03884623609634E-01 7.80726797923763E-01 0.00000000000000E+00
2.19347339382059E-01 6.96215304505741E-01 0.00000000000000E+00
1.81476682591906E-01 6.49928669783620E-01 5.00000000000000E-01
1.17883311021345E-01 5.53637545599493E-01 5.00000000000000E-01
9.13284265134277E-02 5.04116003716147E-01 0.00000000000000E+00
5.07389005586822E-02 4.05964243566022E-01 -4.70197740328915E-38
3.71609228670352E-02 3.57613857671564E-01 5.00000000000000E-01
2.61416858255902E-02 2.66472158453435E-01 5.00000000000000E-01
2.88454394627620E-02 2.24295770070252E-01 0.00000000000000E+00
5.04373025435259E-02 1.50362680181194E-01 -2.35098870164458E-38
6.88804848259828E-02 1.18810105167274E-01 5.00000000000000E-01
1.19143397676256E-01 6.86674604286223E-02 5.00000000000000E-01
1.50723557088132E-01 5.02843449325248E-02 0.00000000000000E+00
2.24654864262447E-01 2.88112554483829E-02 0.00000000000000E+00
2.66804933306564E-01 2.61657336298152E-02 5.00000000000000E-01
3.57859761334254E-01 3.73059527281898E-02 5.00000000000000E-01
4.06149503286051E-01 5.09285387225805E-02 -2.35098870164458E-38
5.04159608941027E-01 9.15081091962600E-02 0.00000000000000E+00
5.53619550019768E-01 1.18004691951257E-01 5.00000000000000E-01
6.49839016529632E-01 1.81448821986422E-01 5.00000000000000E-01
6.96115376390366E-01 2.19273202076238E-01 0.00000000000000E+00
7.80652660617941E-01 3.03784695494259E-01 0.00000000000000E+00
8.18523317408094E-01 3.50071330216380E-01 5.00000000000000E-01
8.82116688978655E-01 4.46362454400507E-01 5.00000000000000E-01
#Exchange-correlation functional

ixc 1 # LDA Teter Pade parametrization

#Definition of the k-point grid
ngkpt 3*2
nshiftk 1
shiftk 0.5 0.5 0.5
#Definition of the planewave basis set

ecut 3.0 # Maximal kinetic energy cut-off, in Hartree


#Definition of the SCF procedure
iscf 7 # Self-consistent calculation, using algorithm 5
nstep 75 # Maximal number of SCF cycles
diemac 9.0 # 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).

end of nano10_10phband.in

The file nano10_10phband.files is looking as follows:

nano10_10phband.in
nano10_10phband.out
nano10_10_phb_i
nano10_10_phb_o
nano10_10phb
../../../Psps_for_tests/06c.pspgth

The calculation is terminating when it reads the WFK file at the beginning of the computation of set 4. In the log file I find

-P-0000 hdr_check: WARNING -
-P-0000 Restart of self-consistent calculation need translated wavefunctions.
-P-0000 Indeed, critical differences between current calculation and
-P-0000 restart file have been detected in:
-P-0000 * the number, position, or weight of k-points
-P-0000 * the format of wavefunctions (istwfk)
-P-0000 ================================================================================
-P-0000
-P-0000 inwffil: ERROR
-P-0000 The file nano10_10_phb_o_DS1_WFK cannot be used to start the
-P-0000 present calculation. It was asked that the wavefunctions be accurate, but
-P-0000 at least one of the k points could not be generated from a symmetrical one.
-P-0000 dksqmax= 2.457418E-03
-P-0000 Action: check your wf file and k point input variables
-P-0000 (e.g. kptopt or shiftk might be wrong in the present dataset or the preparatory one.
-P-0000
-P-0000 leave_new : decision taken to exit ...
-P-0000 leave_new : synchronization done...
-P-0000 leave_new : exiting...


and several lines before:

inwffil : before hdr_check
-P-0000
-P-0000 ================================================================================
-P-0000
-P-0000 - hdr_check: checking restart file header for consistency -
-P-0000
-P-0000
-P-0000 current calculation restart file
-P-0000 ------------------- ------------
-P-0000
-P-0000 calculation expects a wf_planewave | input file contains a wf_planewave
-P-0000 . ABINIT code version 6.2.3 | ABINIT code version 6.2.3
-P-0000 . date 20101111 bantot 680 natom 40 | date 20101111 bantot 170 natom 40
-P-0000 nkpt 8 nsym 4 ngfft 54, 54, 8 | nkpt 2 nsym 4 ngfft 54, 54, 8
-
What am I doing wrong?

Thank you very much for your help,

Greetings,
Joachim Schulte

you have a 2x2x2 k-point grid, but the phonons need the k+q wavefunctions. With q=0.25 0 0 this is impossible. Either use a 4x4x4 mesh (or multiple thereof) or do a non scf calculation of psi_k+q (see tutorials rf1 and rf2) to be read in by getwfq

Matthieu