The ABINIT Users Mailing List ( CLOSED )

["H.Y Liu" <ouuing@gmail.com>]

I think your problem is how to set ngkpt.

On Mon, Dec 7, 2009 at 3:50 AM, Alex Huang <alex.zhen.huang@gmail.com> wrote:
> Dear Abinit users-
>
> This is Alex and I am trying to extract interatomic force constants. I am
> currently interested in Ti.
>
> For Ti I followed the example given in tutorial. The work of RF calculation
> turn out to be OK. However, I have to use nshiftk=4 and
>  shiftk   0.0 0.0 0.5    # This gives the usual fcc Monkhorst-Pack grid
>            0.0 0.5 0.0
>            0.5 0.0 0.0
>            0.5 0.5 0.5
> Instead of recommended
> nshiftk=1 and
>  shiftk   0.0 0.0 0.5    # This gives the usual fcc Monkhorst-Pack grid
> by
> http://www.abinit.org/documentation/helpfiles/for-v5.8/input_variables/varbas.html
>
> Can anyone help me explain this?
>
> On the other hand, even the calculation finished I have many warnings from 
> the
> ##############################################################
>  hdr_check: WARNING -
>  input nkpt=     128 not equal disk file nkpt=      50
>  symafm:                               |  symafm:
>    1  1  1  1  1  1  1  1              |    1  1  1  1  1  1  1  1
>  symrel:                               |  symrel:
>    1  0  0  0  1  0  0  0  1           |    1  0  0  0  1  0  0  0  1
>   -1  0  0  0 -1  0  0  0 -1           |   -1  0  0  0 -1  0  0  0 -1
>    0  1  0  1  0  0  0  0  1           |    0  1  0  1  0  0  0  0  1
>    0 -1  0 -1  0  0  0  0 -1           |    0 -1  0 -1  0  0  0  0 -1
>   -1  0  0  0 -1  0  0  0  1           |   -1  0  0  0 -1  0  0  0  1
>    1  0  0  0  1  0  0  0 -1           |    1  0  0  0  1  0  0  0 -1
>    0 -1  0 -1  0  0  0  0  1           |    0 -1  0 -1  0  0  0  0  1
>    0  1  0  1  0  0  0  0 -1           |    0  1  0  1  0  0  0  0 -1
>  typat:                                |  typat:
>    1  1                                |    1  1
>  so_psp  :                             |  so_psp  :
>    1                                   |    1
>  tnons:                                |  tnons:
>     0.0000000   0.0000000   0.0000000  |     0.0000000   0.0000000   
> 0.0000000
>    -0.3330000   0.3330000   0.5000000  |    -0.3330000   0.3330000   
> 0.5000000
>    -0.3330000   0.3330000   0.5000000  |    -0.3330000   0.3330000   
> 0.5000000
>     0.0000000   0.0000000   0.0000000  |     0.0000000   0.0000000   
> 0.0000000
>    -0.3330000   0.3330000   0.5000000  |    -0.3330000   0.3330000   
> 0.5000000
>     0.0000000   0.0000000   0.0000000  |     0.0000000   0.0000000   
> 0.0000000
>     0.0000000   0.0000000   0.0000000  |     0.0000000   0.0000000   
> 0.0000000
>    -0.3330000   0.3330000   0.5000000  |    -0.3330000   0.3330000   
> 0.5000000
>   znucl:                               |   znucl:
>   22.00                                |   22.00
>  pseudopotential atom type  1:         |  pseudopotential atom type  1:
>  pspso   0 pspxc   1                   |  pspso   0 pspxc   1
>  pspdat 940714 pspcod    1 zion   4.0  |  pspdat 940714 pspcod    1 zion   
> 4.0
>  xred:                                 |  xred:
>     0.0000000   0.0000000   0.0000000  |     0.0000000   0.0000000   
> 0.0000000
>     0.6670000   0.3330000   0.5000000  |     0.6670000   0.3330000   
> 0.5000000
> #############################################################
>
>
>
> The input file is listed below
>
> # Crystalline AlAs : computation of the phonon spectrum
>
>   ndtset   10
> #Set 1 : ground state self-consistency
>
>  getwfk1   0            # Cancel default
>  kptopt1   1            # Automatic generation of k points, taking
>                         # into account the symmetry
>    nqpt1   0            # Cancel default
>  tolvrs1   1.0d-12      # SCF stopping criterion (modify default)
>  rfphon1   0            # Cancel default
>
> #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  0.00000000E+00  0.00000000E+00
> #     qpt5   5.00000000E-01  0.00000000E+00  0.00000000E+00
> #     qpt6   2.50000000E-01  2.50000000E-01  0.00000000E+00
> #     qpt7   5.00000000E-01  2.50000000E-01  0.00000000E+00
> #     qpt8  -2.50000000E-01  2.50000000E-01  0.00000000E+00
> #     qpt9   5.00000000E-01  5.00000000E-01  0.00000000E+00
> #     qpt10 -2.50000000E-01  5.00000000E-01  2.50000000E-01
>
>       qpt2      0.00000000E+00  0.00000000E+00  0.00000000E+00
>       qpt3      0.00000000E+00  0.00000000E+00  0.00000000E+00
>       qpt4      2.50000000E-01  0.00000000E+00  0.00000000E+00
>       qpt5      5.00000000E-01  0.00000000E+00  0.00000000E+00
>       qpt6      2.50000000E-01  2.50000000E-01  0.00000000E+00
>       qpt7      5.00000000E-01  2.50000000E-01  0.00000000E+00
>       qpt8     -2.50000000E-01  2.50000000E-01  0.00000000E+00
>       qpt9      5.00000000E-01  5.00000000E-01  0.00000000E+00
>       qpt10     0.00000000E+00  0.00000000E+00  2.50000000E-01
>       qpt11     2.50000000E-01  0.00000000E+00  2.50000000E-01
>       qpt12     5.00000000E-01  0.00000000E+00  2.50000000E-01
>       qpt13     2.50000000E-01  2.50000000E-01  2.50000000E-01
>       qpt14     5.00000000E-01  2.50000000E-01  2.50000000E-01
>       qpt15    -2.50000000E-01  2.50000000E-01  2.50000000E-01
>       qpt16     5.00000000E-01  5.00000000E-01  2.50000000E-01
>       qpt17     0.00000000E+00  0.00000000E+00  5.00000000E-01
>       qpt18     2.50000000E-01  0.00000000E+00  5.00000000E-01
>       qpt19     5.00000000E-01  0.00000000E+00  5.00000000E-01
>       qpt20     2.50000000E-01  2.50000000E-01  5.00000000E-01
>       qpt21     5.00000000E-01  2.50000000E-01  5.00000000E-01
>       qpt22    -2.50000000E-01  2.50000000E-01  5.00000000E-01
>       qpt23     5.00000000E-01  5.00000000E-01  5.00000000E-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
>  tolvrs2   0.0        # Cancel default for d/dk
>  tolwfr2   1.0d-18    # 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 2        # 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
>
> #Definition of the unit cell
>    acell   5.575 5.575 8.938   # This is equivalent to   2.95a 2.95a 4.73a
>    angdeg  90 90 120
> #    rprim   0.5  -0.866  0.0   # In lessons 1 and 2, these primitive 
> vectors
> #            0.5  0.866  0.0   # (to be scaled by acell) were 1 0 0  0 1 0  
> 0 0
> 1
> #            0.0  0.0  1.0   # that is, the default.
>
> #Definition of the atom types
>    ntypat   1         # There are two types of atom
>    znucl   22     # 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, type 1 is the Titanium
>
> #Definition of the atoms
>    natom   2         # There are two atoms
>    typat   1 1       # The first is of type 1 (Ti), the second is of type 2
> (Ti).
>
>     xred   0.0  0.0  0.0
>            0.667 0.333 0.5
>
> #Gives the number of band, explicitely (do not take the default)
>    nband   40
>
> #Exchange-correlation functional
>
>      ixc   1             # LDA Teter Pade parametrization
>
> #Definition of the planewave basis set
>
>     ecut   25.0           # Maximal kinetic energy cut-off, in Hartree
>
> #Definition of the k-point grid
>    ngkpt   4  4  4
>  nshiftk   4              # Use one copy of grid only (default)
>                           #changed by Alex from 4 to 1
>   shiftk   0.0 0.0 0.5    # This gives the usual fcc Monkhorst-Pack grid
>            0.0 0.5 0.0
>            0.5 0.0 0.0
>            0.5 0.5 0.5
>
> #Definition of the SCF procedure
>     iscf   5          # Self-consistent calculation, using algorithm 5
>    nstep   40         # Maximal number of SCF cycles$$ changed by Alex from 
> 25
> to 125
>   diemac   9.0
>



-- 
-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=**=-=**=-=**=-=*=-=*=-=*=-=*=-=*=-
 Hanyu Liu(刘寒雨),
 MS.
 State key  Laboratory of Superhard Materials, Jilin University, China
 Email: liuhanyu08@mails.jlu.edu.cn    ouuing@gmail.com