[Pw_forum] highest occupied level energy is greater than lowest unoccupied level energy

[Paolo Giannozzi]

If I remember correctly, empty states are not correct
with electric fields

Paolo

On Wed, 2015-02-11 at 01:09 +0600, Khalid Ibne Masood Khalid wrote:
> Dear Researchers,
> 
> I am trying to find out the effect of electric field in the band
> structure of two layers of graphene on diamond. I have relaxed the
> structure, and calculated the scf analysis when an electric field is
> applied. But the bizarre thing is that after scf calculation, it shows
> that the highest occupied level energy is greater than lowest
> unoccupied energy.
>      highest occupied, lowest unoccupied level (ev):     3.8330
> 3.0227
> 
> 
> Here is my input file:
>  &CONTROL
>                  calculation = 'scf' ,
>                 restart_mode = 'from_scratch' ,
>                       outdir =
> '/home/khalid/Desktop/WorkShop-QE/G-D/outdir' ,
>                   pseudo_dir = '/home/khalid/Software/pseudo/' ,
>                       prefix = '0V' ,
>                    verbosity = 'high',
>                      tprnfor = .true. ,
>                           dt = 30.D0 ,
>                forc_conv_thr = 0.5e-3,
>                     lelfield = .true.,
>  /
>  &SYSTEM
>                        ibrav = 4,
>                            A = 2.500D0 ,
>                            C = 35D0 ,
>                          nat = 16,
>                         ntyp = 2,
>                         nbnd = 32,
>                      ecutwfc = 40 ,
>                      ecutrho = 320 ,
>                     vdw_corr = 'Grimme-D2' ,
> 
>  /
>  &ELECTRONS
>                     conv_thr = 1.0D-8 ,
>               diago_full_acc = .true. ,
>               efield_cart(1) = 0.D0 ,
>               efield_cart(2) = 0.D0 ,
>               efield_cart(3) = 7.85773434152D-4,
> 
>  /
>  &IONS
> /
> ATOMIC_SPECIES
>     C   12.01070  C.pbe-rrkjus.UPF 
>     H    1.00079  H.pbe-rrkjus.UPF
> 
> ATOMIC_POSITIONS (crystal)
> H        0.005327839   0.004936103  -0.039898089
> C        0.004926444   0.004582078  -0.008232253
> C        0.671599552   0.337923875   0.005766152
> C        0.671768313   0.338081577   0.050081563
> C        0.338481895   0.671502721   0.064811114
> C        0.338691934   0.671979341   0.108893412
> C        0.005421334   0.005439682   0.123645141
> C        0.005667179   0.005902171   0.167715778
> C        0.672369126   0.339318156   0.182472983
> C        0.672346658   0.339452100   0.226746595
> C        0.339014774   0.672791793   0.240795482
> H        0.339023315   0.672405499   0.272371095
> C        0.335828914   0.671897977   0.349302159
> C        0.002522315   0.005282989   0.349302194
> C        0.002566325   0.005331307   0.451725813
> C        0.335878084   0.671955633   0.451725861
> K_POINTS automatic 
>   12 12 1   1 1 1 
>  
> 
> Is it reasonable to have such kind of result? Did I do something
> wrong ?
> 
> 
> Thanks in advance 
> 
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