Forgive my ignorance is TiO2 known to be a direct gap insulator with valence band top and conduction band bottom at Gamma ? Have you drawn the band structure on the main symmetry lines and compared with experiment/other calculations ?
stefano Quoting #TAO JUNGUANG# <TAOJ0003 at ntu.edu.sg>: > Yes, it is very strange, even it agree very well with the experiment value > (3.2eV). so I am wonder if there are something wrong. And I have double > checked my input file, nothing I have got. So I put important part of my > input/output file in the following, hope there is someone who can help me. > > > > Input file: > &CONTROL > calculation='nscf', > restart_mode='from_scratch', > pseudo_dir='/home/tao/pseudo/', > prefix='TiO2', > tstress=.true. > tprnfor=.true. > / > &SYSTEM > ibrav=6, a=4.594,c=2.958, nat=6,ntyp=2, > ecutwfc=50,ecutrho=300,nbnd=32 > / > &ELECTRONS > conv_thr=1.0d-8, > mixing_beta=0.7, > mixing_mode='plain', > / > > ATOMIC_SPECIES > Ti 47.867 Ti.vdb.UPF > O 15.9994 O.vdb.UPF > > ATOMIC_POSITIONS crystal > Ti 0.00 0.00 0.00 > Ti 0.5 0.5 0.5 > O 0.3053 0.3053 0.00 > O 0.6947 0.6947 0.00 > O 0.1947 0.8053 0.50 > O 0.8053 0.1947 0.50 > K_POINTS > 36 > ......... > Output file > > k = 0.0000 0.0000 0.0000 band energies (ev): > > -48.0513 -48.0328 -24.6394 -24.6394 -24.5918 -24.5555 -24.4560 -24.4560 > -10.8949 -9.9359 -9.1136 -9.1136 1.4513 1.7754 2.9432 3.3134 > 3.3134 4.5065 4.5065 4.9294 5.9502 6.2828 6.2828 6.9172 > 10.1728 10.2878 10.7490 10.7491 10.8082 12.5115 12.6253 14.3036 > > 10.1728-6.9172=3.2556 > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > ---------------------------------------------------------------- SISSA Webmail https://webmail.sissa.it/ Powered by Horde http://www.horde.org/
