The ABINIT Users Mailing List ( CLOSED )

[TORRENT Marc <marc.torrent@cea.fr>]

Dear Hua,
Let me point out that the pseudopotentials delivered in the 
Psps_for_test directory are "test pseudopotentials" and are susceptible 
to give unphysical results; they are only present in order to test 
specific parts of the code ...
You should use a pseudopotential from the PAW atomicdata table (see 
abinit.org).
The error you mention (Density went < 0) can disappear with the use of 
another PAW dataset..

Marc Torrent

Hua Bao a écrit :
> Dear abinit-user,
>
> I was trying to calculate linear optic properties for (5,0) carbon 
> nanotube (structure was optimized by abinit). I used the input file 
> similar with the test input toptic_3.in in the "\tests\tutorespfn" 
> folder. Pseudopotential files was chosen to be "6c_lda.paw" in the 
> psp_for_test in abinit package. There are totally 6 data sets. But the 
> program stopped at the 3rd data set.The last a few lines of log file are,
>
> FFT (fine) grid used in SCF cycle:
> getcut: wavevector=  0.0000  0.0000  0.0000  ngfft= 135 135  60
>         ecut(hartree)=     60.000   => boxcut(ratio)=   2.03360
>
> mkdenpos : WARNING -
>  Density went < 0 at     17898 points
>  and was set to  1.00E-14.  Lowest was  -0.37E-05.
>  Likely due to too low boxcut or too low ecut for pseudopotential core 
> charge.
> p1_7101:  p4_error: interrupt SIGSEGV: 11
> rm_l_1_7104: (35065.222656) net_send: could not write to fd=5, errno = 32
> p1_7101: (35065.222656) net_send: could not write to fd=5, errno = 32
>
>
> I am using parallel running (abinip). Thus, I changed the ecut and box 
> size for a few times but they were still stuck here. Would anyone 
> please give me some suggestions on choosing appropriate parameters?
>
> Here is the input file,
>
> ndtset 6
>
> #First dataset : SC run with kpoints in the IBZ
>  nband1  80     nstep1 200  kptopt1 1
> nbdbuf1 0
> prtden1 1   getden1 0   getwfk1 0    ! Usual file handling data
>
> #Second dataset : NSC run with large number of bands, and points in 
> the IBZ
>    iscf2 -2   nband2 80  ! Minimal number of bands for linear optics 
> (imaginary part of the spectrum)
>   nstep2 200
>  kptopt2  1
>  getwfk2  1   getden2 1   ! Usual file handling data
>
> #Third dataset : NSC run with large number of bands, and points in the 
> the full BZ
>    iscf3 -2   nband3 80  ! Minimal number of bands for linear optics 
> (imaginary part of the spectrum)
>   nstep3 200
>  kptopt3  2  ! Time-reversal symmetry can be used in the present 
> implementation for linear optics
>  getwfk3  2   getden3 1   ! Usual file handling data
>
>
> #Fourth dataset : ddk response function along axis 1
>   iscf4 -3
>  nband4  80   ! Minimal number of bands for linear optics (imaginary 
> part of the spectrum)
>  nstep4  1
>  nline4  0
> kptopt4  2   ! Time-reversal symmetry can be used in the present 
> implementation for linear optics
>
>   nqpt4  1  qpt4  0.0d0 0.0d0 0.0d0
>  rfdir4  1 0 0
> rfelfd4  2
> getwfk4  3
>
> #Fifth dataset : ddk response function along axis 2
>   iscf5 -3
>  nband5  80   ! Minimal number of bands for linear optics (imaginary 
> part of the spectrum)
>  nstep5  1  nline5  0
> kptopt5  2   ! Time-reversal symmetry can be used in the present 
> implementation for linear optics
>
>   nqpt5  1  qpt5  0.0d0 0.0d0 0.0d0
>  rfdir5  0 1 0
> rfelfd5  2
> getwfk5  3
> rfdir5  0 1 0
> rfelfd5  2
> getwfk5  3
>
> # Sixth dataset : ddk response function along axis 3
>   iscf6 -3
>  nband6  80   ! Minimal number of bands for linear optics (imaginary 
> part of the spectrum)
>  nstep6  1  nline6  0
> kptopt6  2   ! Time-reversal symmetry can be used in the present 
> implementation for linear optics
>
>   nqpt6  1  qpt6  0.0d0 0.0d0 0.0d0
>  rfdir6  0 0 1
> rfelfd6  2
> getwfk6  3
>
>
> #Data common to all datasets
> ngkpt  3*4      ! This is much too low : should be at least 24x24x24
>
> acell 10 10 4.24 angstrom
> ! amu 69.72  74.9216
> ecut 30.00       pawecutdg 60.0    ! iscf 3
> natom  20 ntypat  1
> ! rprim   0 .5 .5  .5 0 .5  .5 .5 0
>
> xangst  ........
>
> typat  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
> tolwfr  1.e-12
> znucl  6
>
>
>
> Thanks,
>
> Hua