The ABINIT Users Mailing List ( CLOSED )

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

try to set occopt 7 or 6   and tsmear .
you'd better test value of tsmear.


On Mon, Dec 7, 2009 at 3:58 AM, Alex Huang <alex.zhen.huang@gmail.com> wrote:
> Dear users and developers-
>
> I am calculating Response Function of Graphene Nanoribbon. Seems the SCF
> calculation is hard to converge. Can you help me look at why is it?
>
> Thanks for helping
> Warnings-
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>  scfcge: WARNING -
>  Potential-based CG line minimization has trouble to converge.
>  The algorithm is restarted with more secure parameters.
>  scfcge: actual    13-6-1   4.1250E-01 -4.501096672356E+01  7.9239E-01
>  scfcge: predict           -6.6216E-01 restart the algorithm
>  scfcge:
>  scfcge: start     13-7-0   0.0000E+00 -4.501096672356E+01  7.9239E-01
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>
>
> #######################################################
>  scfcge : ERROR -
>  Potential-based CG line minimization not converged after 13 restarts.
>  Action : read the eventual warnings about lack of convergence.
>  Some might be relevant. Otherwise, raise nband.
> ##################### ####################################
>
> 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-18      # 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     0.00000000E+00  0.00000000E+00  6.25000000E-02
>      qpt5     0.00000000E+00  0.00000000E+00  1.25000000E-01
>      qpt6     0.00000000E+00  0.00000000E+00  1.87500000E-01
>      qpt7     0.00000000E+00  0.00000000E+00  2.50000000E-01
>      qpt8     0.00000000E+00  0.00000000E+00  3.12500000E-01
>      qpt9     0.00000000E+00  0.00000000E+00  3.75000000E-01
>      qpt10    0.00000000E+00  0.00000000E+00  4.37500000E-01
>      qpt11    0.00000000E+00  0.00000000E+00  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-22    # 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 3 4 5 6 7 8    # 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  60.36 16.08 8.04         # This is equivalent to   10.61 10.61 
> 10.61
>    angdeg 90 90 90
> #    rprim   0.0  0.5  0.5   # In lessons 1 and 2, these primitive vectors
> #            0.5  0.0  0.5   # (to be scaled by acell) were 1 0 0  0 1 0  0 
> 0 1
>
> #            0.5  0.5  0.0   # that is, the default.
>
> #Definition of the atom types
>   ntypat   1         # There are two types of atom
>    znucl   6
>
> #Definition of the atoms
>    natom   8         # There are two atoms
>    typat   1 1 1 1 1 1 1 1     # The first is of type 1 (Al), the second is 
> of
> type 2 (As).
>
>     xred   0.462  0.5  0.000
>            0.538  0.5  0.000
>            0.462  0.5  0.333
>            0.538  0.5  0.333
>            0.500  0.5  0.500
>            0.577  0.5  0.500
>            0.500  0.5  0.833
>            0.577  0.5  0.833
> #Gives the number of band, explicitely (do not take the default)
>    nband   40
>
> #Exchange-correlation functional
>
>      ixc   1
>     ecut   25.0           # Maximal kinetic energy cut-off, in Hartree
>
> #Definition of the k-point grid
>    ngkpt   1  1  16
>  nshiftk   1              # 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
>
>
> #Definition of the SCF procedure
>     iscf   5          # Self-consistent calculation, using algorithm 5
>    nstep   100         # Maximal number of SCF cycles
>   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