<div dir="ltr"><div class="gmail_quote"><div dir="ltr"><div dir="ltr">Hello dear experts,<div>Hope you are doing well.</div><div><br></div><div>I was trying to calculate the DOS in hexagonal Cr2O3, the DOS is coming very well with a bandgap of 3.09, but the problem is the Fermi level is at the edge of LUMO whereas I've observed that it should be at HUMO edge in few already published papers. </div><div>I used PBE NC SR pseudopotential and also optimized with the same. I used gaussian smearing with a width of 0.001 in VC-relax and tetrahedra in SCF calculation.</div><div><br></div><div>Here is my input file -</div><div><br></div><div>&CONTROL<br>    calculation   = "scf"<br>    pseudo_dir    = "./"<br>    outdir        = "./outdir"<br>/<br><br>&SYSTEM<br>    a                         =  4.6166825e+00<br>    c                         =  1.2457778e+01<br>    ecutrho                   =  4.5000e+02<br>    ecutwfc                   =  4.5000e+01<br>    ibrav                     = 4<br>    nat                       = 30<br>    nspin                     = 2<br>    ntyp                      = 3<br>    nbnd                      = 276<br>    starting_magnetization(1) = 0.5<br>    starting_magnetization(2) = -0.5<br>    starting_magnetization(3) = 0.0 <br>    tot_magnetization         = 0.0<br>    lda_plus_u                = .true.<br>    Hubbard_U(1)              = 4.7<br>    Hubbard_U(2)              = 4.7<br>    Hubbard_J0(1)             = 1<br>    Hubbard_J0(2)             = 1<br>/<br><br>&ELECTRONS<br>    conv_thr         =  1.00000e-11<br>    electron_maxstep = 2000<br>    mixing_beta      =  7.00000e-01<br>    startingpot      = "atomic"<br>    startingwfc      = "atomic+random"<br>/<br><br><br>K_POINTS {automatic}<br> 12 12 12  0 0 0<br><br>ATOMIC_SPECIES<br>Cr1    51.99610  Cr.upf<br>Cr2    51.99610  Cr.upf<br>O      15.99940  O.upf<br><br>ATOMIC_POSITIONS (angstrom)<br>Cr2          -0.0000027528        2.6654550870        3.9638155751<br>Cr1           2.3083528721        1.3327252495        2.2651020880<br>Cr1          -0.0000027528        2.6654550870        0.1887989665<br>Cr2           0.0000000000        0.0000000000        1.8875092202<br>Cr2           0.0000000000        0.0000000000        8.1164268017<br>Cr1          -0.0000027528        2.6654550870        6.4177165986<br>Cr1           0.0000000000       -0.0000000000        4.3414084067<br>Cr2           2.3083528721        1.3327252495        6.0401185402<br>Cr2           2.3083528721        1.3327252495       12.2690363475<br>Cr1           0.0000000000        0.0000000000       10.5703258606<br>Cr1           2.3083528721        1.3327252495        8.4940197683<br>Cr2          -0.0000027528        2.6654550870       10.1927331413<br>O             1.4445126756        0.0000000398        3.1144588851<br>O             3.0306076646        0.0817435268        1.0381518347<br>O             0.8638388763        1.3327251470        1.0381518347<br>O             3.0306056520        2.5837116627        1.0381518347<br>O            -0.7222568310        1.2509851988        3.1144588851<br>O             1.5860942747        2.7471960155        3.1144588851<br>O             3.7528623252        1.3327254382        7.2670694393<br>O             0.7222547656        1.4144695631        5.1907658203<br>O            -1.4445122603        2.6654550733        5.1907658203<br>O             0.7222574947        3.9164369542        5.1907658203<br>O             1.5860961469        2.5837115564        7.2670694393<br>O             1.5860937210        0.0817433419        7.2670694393<br>O             1.4445122976        2.6654551364       11.4196834856<br>O            -1.5860942579        2.7471959172        9.3433763434<br>O             0.8638382678        3.9981804108        9.3433763434<br>O             0.7222569078        1.2509852624        9.3433763434<br>O            -0.7222575680        3.9164369549       11.4196834856<br>O            -0.7222547296        1.4144694992       11.4196834856<br><br></div><div><br></div><div>I later tried with pw91 USPP, it fixed the fermi level position (it's now at HUMO edge) but the bad gap is now very underestimated to 2.3 eV.</div><div><br></div><div>I tried paw but it wasn't working with me.</div><div><br></div><div>Can someone please help?</div><div><br></div><div>Regards</div><div>Yuvam Bhateja</div><div>IIEST Shibpur</div><div>India</div></div></div>
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