Hi, As you have an oxide it is not so surprising. As an example I remember B1 NiO or FeO.
You should apply, at least, LDA+U to get more correct bands (see /examples/example25). Yamboo or GW+Wannier might be another tools to fix the problem. Bests, Eyvaz. ------------------------------------------------------------------- Prof. Eyvaz Isaev, Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com ________________________________ From: sonu kumar <1009uku...@gmail.com> To: pw_forum at pwscf.org Sent: Mon, November 1, 2010 6:54:50 AM Subject: [Pw_forum] odd # of electrons in primitive cell => metal ? Dear all QE users, My primitive unit cell contains odd # of electrons so it should be metallic. QE code indicates the system to be metallic. But experimentally it is an insulator with band gap ~1.2 eV. why am i not able to get the insulating nature of the system? IS there something wrong in the input file? or in DFT? ################################################################### PARTs OF input n output file are: &control calculation='scf', ! relax,scf,vc-relax verbosity='high', restart_mode='from_scratch', ! 'from_scratch', prefix='CuFeO2', !wf_collect=.true., tstress=.true., tprnfor=.true., etot_conv_thr=1.0D-6, forc_conv_thr=1.0D-5, pseudo_dir = './pseudo', outdir='./tmp', / &system ibrav=5,celldm(1)=11.31, celldm(4)=0.8718, nat= 4, ntyp= 3, !nbnd=24, ecutwfc=40, ecutrho=400, !occupations = 'smearing', !degauss = 0.005D0, !smearing='gaussian', nspin=1, / &electrons electron_maxstep=100, mixing_mode='local-TF', mixing_beta = 0.2, conv_thr = 1.0d-12, mixing_ndim=8, diagonalization='cg', / ATOMIC_SPECIES Cu 0.0 Cu.pbe-n-van_ak.UPF Fe 0.0 Fe.pbe-sp-van.UPF O 0.0 O.pbe-rrkjus.UPF ..... .... !!!!!!!!!!!!!!!!!!!!!! Part of ouput file !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% from electrons : error # 1 stopping ... charge is wrong: smearing is needed %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ##################################################################### With Kind regards, Sonu Kumar Phd Student Physics Department Indian Institute of Technology Delhi-110016, India web:-http://www.iitd.ac.in/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101101/d7fcffb6/attachment.htm