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--></style></head><body lang=EN-US link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'>Dear Yuvam <o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'>When one uses smeared occupations in systems with a large gap ( significantly larger than the smearing) the final value of the Fermi level returned from the calculation may be any value within the band gap sufficiently far from the band edges (HOMO and LUMO). All the values in this range yield the same values for the occupations and thus of the ground state density. If you wish you can decide to follow the convention of the other papers and refer to the HOMO as the Fermi level. <o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'>In fact in insulators the thermodynamic Fermi level depends on extrinsic conditions such as doping or defect concentrations and on the temperature. All things which are obviously not taken into account in your calculation. <o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'>Kind regards <o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'>Pietro <o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal>Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986">Mail</a> for Windows 10</p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'><o:p> </o:p></span></span></p><div style='mso-element:para-border-div;border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='border:none;padding:0in'><b>From: </b><a href="mailto:yuvamb16@gmail.com">Yuvam Bhateja</a><br><b>Sent: </b>Thursday, July 23, 2020 12:44 PM<br><b>To: </b><a href="mailto:users@lists.quantum-espresso.org">Quantum ESPRESSO users Forum</a><br><b>Subject: </b>[QE-users] Wrong position of fermi level in bulk Cr2O3</p></div><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'><o:p> </o:p></span></span></p><div><div><p class=MsoNormal>Hello dear experts,</p><div><p class=MsoNormal>Hope you are doing well.</p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>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. </p></div><div><p class=MsoNormal>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.</p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Here is my input file -</p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'>&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</p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>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.</p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I tried paw but it wasn't working with me.</p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Can someone please help?</p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Regards</p></div><div><p class=MsoNormal>Yuvam Bhateja</p></div><div><p class=MsoNormal>IIEST Shibpur</p></div></div></div><p class=MsoNormal>India</p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:12.0pt'><o:p> </o:p></span></span></p></div></body></html>