Hey Giacomo, Forgive my ignorance but why do you say that the "scf" calculation is a system that "should be" metallic ? To me it has a band gap of .7 ev. What do you mean by wide band gap semiconductor ? What band gap value do you expect to get? May be the wide band gap behavior you mention does not occur at 0K. I guess you double checked whether your system is fully relaxed.
?ric. On 12/02/2011 09:20 PM, giacsport at libero.it wrote: > Dear All, > I am doing calculations on a 2 atom primitive cell of Boron > Phosphide. What I obtain from the "scf" calculation is a system that "should > be" metallic.... Indeed > > "highest occupied, lowest unoccupied level (ev): 6.1092 > 5.4104" -->( As far as I understand, Homo lies 0.7 eV above > the > LUMO) > > but of course this system is a wide-gap semiconductor. > I am not able to figure out the reason for such behaviour. I have tested the > same system (rhombohedral cell, a=b=c=6.06 Bohr, alpha=beta=gamma=60deg) in > several machines finding always the same result. I attach the input file and > the header of the two pseudos (USPP/GGA) I am using. > Thanks in advance for any comments. > My best, > Giacomo > > > > > > > &control > calculation = 'scf' > restart_mode='from_scratch', > prefix='BP', > tprnfor = .true., > tstress = .true., > wf_collect=.true., > pseudo_dir='/home/giacomo/GGA/', > outdir='/home/giacomo/GGA/' > / > &system > ibrav= 4, celldm(1) =6.061296108, celldm(3)=1, > nat= 2, ntyp= 2, > ecutwfc =50., nbnd = 50, > / > &electrons > diagonalization='david' > mixing_mode = 'plain' > mixing_beta = 0.7 > conv_thr = 1.0d-8 > / > ATOMIC_SPECIES > B 10.811 B.UPF > P 30.974 P.UPF > ATOMIC_POSITIONS (crystal) > B 0.0 0.0 0.0 > P 0.25000 0.25000 0.250000 > K_POINTS (automatic) > 6 6 6 0 0 0 > > > > > > > > > For BORON: > > <PP_INFO> > Generated using Vanderbilt code, version 7 3 5 > Author: unknown Generation date: 20 6 2004 > Automatically converted from original format > 0 The Pseudo was generated with a Non-Relativistic Calculation > 1.00000000000E+00 Local Potential cutoff radius > nl pn l occ Rcut Rcut US E pseu > 2S 2 0 2.00 10.00000000000 1.50000000000 -0.69693392995 > 2P 2 1 1.00 10.00000000000 1.53000000000 -0.26855658626 > </PP_INFO> > > > <PP_HEADER> > 0 Version Number > B Element > US Ultrasoft pseudopotential > T Nonlinear Core Correction > SLA PW GGX GGC PW91 Exchange-Correlation functional > 3.00000000000 Z valence > -5.70038942945 Total energy > 0.0000000 0.0000000 Suggested cutoff for wfc and rho > 1 Max angular momentum component > 781 Number of points in mesh > 2 4 Number of Wavefunctions, Number of Projectors > Wavefunctions nl l occ > 2S 0 2.00 > 2P 1 1.00 > </PP_HEADER> > --------------------------------- > > > > For PHOSPHORUS > > <PP_INFO> > Generated using Vanderbilt code, version 7 3 5 > Author: unknown Generation date: 20 6 2004 > Automatically converted from original format > 1 The Pseudo was generated with a Scalar-Relativistic Calculation > 1.60000000000E+00 Local Potential cutoff radius > nl pn l occ Rcut Rcut US E pseu > 3S 3 0 2.00 10.00000000000 1.70000000000 -1.03015496458 > 3P 3 1 3.00 10.00000000000 1.70000000000 -0.40774343239 > </PP_INFO> > > > <PP_HEADER> > 0 Version Number > P Element > US Ultrasoft pseudopotential > T Nonlinear Core Correction > SLA PW GGX GGC PW91 Exchange-Correlation functional > 5.00000000000 Z valence > -17.57767183737 Total energy > 0.0000000 0.0000000 Suggested cutoff for wfc and rho > 2 Max angular momentum component > 903 Number of points in mesh > 2 5 Number of Wavefunctions, Number of Projectors > Wavefunctions nl l occ > 3S 0 2.00 > 3P 1 3.00 > </PP_HEADER> > > > > ------------------------------------------ > Giacomo Giorgi > > Department of Chemical System Engineering, > School of Engineering, The University of Tokyo > 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- /Be the change you wish to see in the world / --- Mahatma Gandhi --- Dr. ?ric Germaneau <http://www.linkedin.com/pub/%C3%A9ric-germaneau/30/931/986> Graduate University of Chinese Academy of Sciences College of Physical Sciences Yuquan Road 19A Beijing 100049 China /Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20111203/26afe8dd/attachment-0001.htm