I'm sorry, you expressed correctly. Can you tell us what pressure and forces you got? What was energy difference between the two last scf steps?
?ric. On 12/03/2011 03:39 AM, giacsport at libero.it wrote: > > Hi Eric, > > sorry. I expressed my point maybe in a > misleading way...I mean, i found a gap metallic (Homo is highest in > energy than Lumo) but the system is reported to be a wide bandgap > semiconductor (Gap > 2. eV) > > "highest occupied, lowest unoccupied level (ev): 6.1092 5.4104" > > HOMO=6.109 LUMO=5.4104 (as far as I understand)....the gap is 0.7 eV > only if you switch HOMO and LUMO > > The structure is the experimental one I found from a previous paper > and it was optimized with Gaussian PBC > > > Thanks, > > G > > > ----Messaggio originale---- > Da: germaneau at gucas.ac.cn > Data: 03/12/2011 16.32 > A: "giacsport at libero.it"<giacsport at libero.it>, "PWSCF > Forum"<pw_forum at pwscf.org> > Ogg: Re: [Pw_forum] metallic BP? > > 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? 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