<div dir="ltr"><div><div><div>I am posting this again, because I forgot to write my affiliation<br><br><div><div><div><div>Dear Researchers,<br></div>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.<br>     highest occupied, lowest unoccupied level (ev):     3.8330    3.0227<br><br></div>Here is my input file:<br> &CONTROL<br>                 calculation = 'scf' ,<br>                restart_mode = 'from_scratch' ,<br>                      outdir = '/home/khalid/Desktop/WorkShop-QE/G-D/outdir' ,<br>                  pseudo_dir = '/home/khalid/Software/pseudo/' ,<br>                      prefix = '0V' ,<br>                   verbosity = 'high',<br>                     tprnfor = .true. ,<br>                          dt = 30.D0 ,<br>               forc_conv_thr = 0.5e-3,<br>                    lelfield = .true.,<br> /<br> &SYSTEM<br>                       ibrav = 4,<br>                           A = 2.500D0 ,<br>                           C = 35D0 ,<br>                         nat = 16,<br>                        ntyp = 2,<br>                        nbnd = 32,<br>                     ecutwfc = 40 ,<br>                     ecutrho = 320 ,<br>                    vdw_corr = 'Grimme-D2' ,<br><br> /<br> &ELECTRONS<br>                    conv_thr = 1.0D-8 ,<br>              diago_full_acc = .true. ,<br>              efield_cart(1) = 0.D0 ,<br>              efield_cart(2) = 0.D0 ,<br>              efield_cart(3) = 7.85773434152D-4,<br><br> /<br> &IONS<br>/<br>ATOMIC_SPECIES<br>    C   12.01070  C.pbe-rrkjus.UPF <br>    H    1.00079  H.pbe-rrkjus.UPF<br><br>ATOMIC_POSITIONS (crystal)<br>H        0.005327839   0.004936103  -0.039898089<br>C        0.004926444   0.004582078  -0.008232253<br>C        0.671599552   0.337923875   0.005766152<br>C        0.671768313   0.338081577   0.050081563<br>C        0.338481895   0.671502721   0.064811114<br>C        0.338691934   0.671979341   0.108893412<br>C        0.005421334   0.005439682   0.123645141<br>C        0.005667179   0.005902171   0.167715778<br>C        0.672369126   0.339318156   0.182472983<br>C        0.672346658   0.339452100   0.226746595<br>C        0.339014774   0.672791793   0.240795482<br>H        0.339023315   0.672405499   0.272371095<br>C        0.335828914   0.671897977   0.349302159<br>C        0.002522315   0.005282989   0.349302194<br>C        0.002566325   0.005331307   0.451725813<br>C        0.335878084   0.671955633   0.451725861<br>K_POINTS automatic <br>  12 12 1   1 1 1 <br> <br></div>Is it reasonable to have such kind of result? Did I do something wrong ?<br><br></div>Thanks in advance <br><br></div>Khalid Ibne Masood<br></div>M.Sc student<br></div>BUET<br></div>