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

[Khalid Ibne Masood Khalid]

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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