[Pw_forum] Too many bands are not converged from nscf calculation

giuseppe.mattioli at mlib.ism.cnr.it giuseppe.mattioli at mlib.ism.cnr.it
Sun Sep 25 21:12:38 CEST 2011


Dear Zhiting

>    ibrav= 1, celldm(1)= 22.52, nat= 64, ntyp= 3, nbnd=18

your 64-atom alloy supercell should contain much more than 18 occupied  
bands. If you want to calculate 18 unoccupied bands you should set the  
nband parameter to "number_of_occupied_levels+18".
HTH

Giuseppe

Giuseppe Mattioli
ISM-CNR
Italy

Citando Zhiting Tian <zhiting at MIT.EDU>:

> Dear all,
>
> I first did scf calculation and it finished. Then I run nscf,  but   
> always got error message: "Too many bands are not converged" and   
> then it stopped.
> I had read a few posts before and tried to reduce mixing-beta from   
> 0.7 to 0.4 and even to 0.05, but same error. Also, I have tried to   
> change the diagolization='david' to 'cg', same error.
>
> My input files are following:
> scf_in:
>
>  &control
>    calculation = 'scf'
>    restart_mode='from_scratch'
>    prefix='PbSeAl'
>    tstress = .true.
>    tprnfor = .true.
>    pseudo_dir = "..."
>    outdir = "..."
> /
>  &system
>    ibrav= 1, celldm(1)= 22.52, nat= 64, ntyp= 3 ,
>    ecutwfc = 60,
>    noncolin = .TRUE.
>    lspinorb = .TRUE.
>    occupations = 'smearing'
>    smearing = 'mv'
>    degauss = 0.01
> /
>  &electrons
>    mixing_beta = 0.7D0
>    conv_thr = 1.0d-10
> /
> ATOMIC_SPECIES
> Al 26.98 Al.rel-pz-nc.UPF
> Pb 207.21 Pb.rel-pz-nc.UPF
> Se 78.96 Se.rel-pz-nc.UPF
>
> ATOMIC_POSITIONS
> Al 0.000000 0.000000 0.000000
> Pb 0.500000 0.000000 0.000000
> Pb 0.250000 0.250000 0.000000
> Pb 0.750000 0.250000 0.000000
> Pb 0.000000 0.500000 0.000000
> Pb 0.500000 0.500000 0.000000
> Pb 0.250000 0.750000 0.000000
> Pb 0.750000 0.750000 0.000000
> Pb 0.250000 0.000000 0.250000
> Pb 0.750000 0.000000 0.250000
> Pb 0.000000 0.250000 0.250000
> Pb 0.500000 0.250000 0.250000
> Pb 0.250000 0.500000 0.250000
> Pb 0.750000 0.500000 0.250000
> Pb 0.000000 0.750000 0.250000
> Pb 0.500000 0.750000 0.250000
> Pb 0.000000 0.000000 0.500000
> Pb 0.500000 0.000000 0.500000
> Pb 0.250000 0.250000 0.500000
> Pb 0.750000 0.250000 0.500000
> Pb 0.000000 0.500000 0.500000
> Pb 0.500000 0.500000 0.500000
> Pb 0.250000 0.750000 0.500000
> Pb 0.750000 0.750000 0.500000
> Pb 0.250000 0.000000 0.750000
> Pb 0.750000 0.000000 0.750000
> Pb 0.000000 0.250000 0.750000
> Pb 0.500000 0.250000 0.750000
> Pb 0.250000 0.500000 0.750000
> Pb 0.750000 0.500000 0.750000
> Pb 0.000000 0.750000 0.750000
> Pb 0.500000 0.750000 0.750000
> Se 0.250000 0.000000 0.000000
> Se 0.750000 0.000000 0.000000
> Se 0.000000 0.250000 0.000000
> Se 0.500000 0.250000 0.000000
> Se 0.250000 0.500000 0.000000
> Se 0.750000 0.500000 0.000000
> Se 0.000000 0.750000 0.000000
> Se 0.500000 0.750000 0.000000
> Se 0.000000 0.000000 0.250000
> Se 0.500000 0.000000 0.250000
> Se 0.250000 0.250000 0.250000
> Se 0.750000 0.250000 0.250000
> Se 0.000000 0.500000 0.250000
> Se 0.500000 0.500000 0.250000
> Se 0.250000 0.750000 0.250000
> Se 0.750000 0.750000 0.250000
> Se 0.250000 0.000000 0.500000
> Se 0.750000 0.000000 0.500000
> Se 0.000000 0.250000 0.500000
> Se 0.500000 0.250000 0.500000
> Se 0.250000 0.500000 0.500000
> Se 0.750000 0.500000 0.500000
> Se 0.000000 0.750000 0.500000
> Se 0.500000 0.750000 0.500000
> Se 0.000000 0.000000 0.750000
> Se 0.500000 0.000000 0.750000
> Se 0.250000 0.250000 0.750000
> Se 0.750000 0.250000 0.750000
> Se 0.000000 0.500000 0.750000
> Se 0.500000 0.500000 0.750000
> Se 0.250000 0.750000 0.750000
> Se 0.750000 0.750000 0.750000
>
> K_POINTS (automatic)
>  4 4 4  0 0 0
>
> nscf_in:
>
>  &control
>    calculation = 'nscf'
>    prefix='PbSeAl'
>    tstress = .true.
>    tprnfor = .true.
>    pseudo_dir = "..."
>    outdir = "..."
> /
>  &system
>    ibrav= 1, celldm(1)= 22.52, nat= 64, ntyp= 3, nbnd=18
>    ecutwfc = 60,
>    noncolin = .TRUE.
>    lspinorb = .TRUE.
>    occupations = 'tetrahedra'
> /
>  &electrons
>    mixing_beta = 0.05D0
>    conv_thr = 1.0d-10
>    diagonalization = 'david'
> /
> ATOMIC_SPECIES
> Al 26.98 Al.rel-pz-nc.UPF
> Pb 207.21 Pb.rel-pz-nc.UPF
> Se 78.96 Se.rel-pz-nc.UPF
>
> ATOMIC_POSITIONS
> Al 0.000000 0.000000 0.000000
> Pb 0.500000 0.000000 0.000000
> Pb 0.250000 0.250000 0.000000
> Pb 0.750000 0.250000 0.000000
> Pb 0.000000 0.500000 0.000000
> Pb 0.500000 0.500000 0.000000
> Pb 0.250000 0.750000 0.000000
> Pb 0.750000 0.750000 0.000000
> Pb 0.250000 0.000000 0.250000
> Pb 0.750000 0.000000 0.250000
> Pb 0.000000 0.250000 0.250000
> Pb 0.500000 0.250000 0.250000
> Pb 0.250000 0.500000 0.250000
> Pb 0.750000 0.500000 0.250000
> Pb 0.000000 0.750000 0.250000
> Pb 0.500000 0.750000 0.250000
> Pb 0.000000 0.000000 0.500000
> Pb 0.500000 0.000000 0.500000
> Pb 0.250000 0.250000 0.500000
> Pb 0.750000 0.250000 0.500000
> Pb 0.000000 0.500000 0.500000
> Pb 0.500000 0.500000 0.500000
> Pb 0.250000 0.750000 0.500000
> Pb 0.750000 0.750000 0.500000
> Pb 0.250000 0.000000 0.750000
> Pb 0.750000 0.000000 0.750000
> Pb 0.000000 0.250000 0.750000
> Pb 0.500000 0.250000 0.750000
> Pb 0.250000 0.500000 0.750000
> Pb 0.750000 0.500000 0.750000
> Pb 0.000000 0.750000 0.750000
> Pb 0.500000 0.750000 0.750000
> Se 0.250000 0.000000 0.000000
> Se 0.750000 0.000000 0.000000
> Se 0.000000 0.250000 0.000000
> Se 0.500000 0.250000 0.000000
> Se 0.250000 0.500000 0.000000
> Se 0.750000 0.500000 0.000000
> Se 0.000000 0.750000 0.000000
> Se 0.500000 0.750000 0.000000
> Se 0.000000 0.000000 0.250000
> Se 0.500000 0.000000 0.250000
> Se 0.250000 0.250000 0.250000
> Se 0.750000 0.250000 0.250000
> Se 0.000000 0.500000 0.250000
> Se 0.500000 0.500000 0.250000
> Se 0.250000 0.750000 0.250000
> Se 0.750000 0.750000 0.250000
> Se 0.250000 0.000000 0.500000
> Se 0.750000 0.000000 0.500000
> Se 0.000000 0.250000 0.500000
> Se 0.500000 0.250000 0.500000
> Se 0.250000 0.500000 0.500000
> Se 0.750000 0.500000 0.500000
> Se 0.000000 0.750000 0.500000
> Se 0.500000 0.750000 0.500000
> Se 0.000000 0.000000 0.750000
> Se 0.500000 0.000000 0.750000
> Se 0.250000 0.250000 0.750000
> Se 0.750000 0.250000 0.750000
> Se 0.000000 0.500000 0.750000
> Se 0.500000 0.500000 0.750000
> Se 0.250000 0.750000 0.750000
> Se 0.750000 0.750000 0.750000
>
> K_POINTS (automatic)
>  8 8 8  0 0 0
>
>
> Can anyone help me with this?
>
> Thanks a lot,
> Zhiting Tian
> PhD student
> Mechanical Engineering Department
> Massachusetts Institute of Technology
> Email: zhiting at mit.edu
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