On Fri, 2009-04-03 at 20:16 +0800, ??? wrote: > Dear dalcorso, > Thank you for your detailed reply. The initial output I posted > is not consistent with your output because I changed the > "starting_magnetization=0.00," to 0.01. Though the energy is the same, > the symmetry is different. I recalculate it with > "starting_magnetization=0.00," and the output is same as your output. > > In addition, I want to know how to calculate the exciton energy > level ? Is that possible in recent pwscf? > As far as I know the answer is no. But maybe somebody else knows better than me how to do this.
Andrea > 2009/4/3 Dal Corso Andrea <dalcorso at sissa.it> > > On my PC, with your input I obtain: > > &plot nbnd= 30, nks= 1 / > 0.000000 0.000000 0.000000 > -8.070 -8.070 -5.968 -5.968 1.092 1.092 6.154 > 6.154 6.169 > 6.169 > > 6.802 6.802 6.816 6.816 7.016 7.016 11.136 > 11.136 13.603 > 13.603 > 17.514 17.514 18.094 18.094 18.118 18.118 19.967 > 19.967 20.042 > 20.042 > > That compare quite well with your bands: > > &plot nbnd= 30, nks= 1 / > 0.000000 0.000000 0.000000 > -8.070 -8.070 -5.968 -5.968 1.092 1.092 6.154 > 6.154 6.169 > 6.169 > 6.803 6.803 6.816 6.816 7.015 7.015 11.136 > 11.136 13.603 > 13.603 > 17.513 17.513 18.094 18.094 18.118 18.118 19.967 > 19.967 20.042 > 20.042 > > > The output of bands.x says that the code is using the group > C_6v > to classify the bands > > xk=( 0.00000, 0.00000, 0.00000 ) > > double point group C_6v (6mm) > there are 9 classes and 3 irreducible representations > the character table: > > E -E C2 2C3 -2C3 2C6 -2C6 3s_v 3s_d > -C2 -3s_v -3s_d > G_7 2.00 -2.00 0.00 1.00 -1.00 1.73 -1.73 0.00 0.00 > G_8 2.00 -2.00 0.00 1.00 -1.00 -1.73 1.73 0.00 0.00 > G_9 2.00 -2.00 0.00 -2.00 2.00 0.00 0.00 0.00 0.00 > > That has only three representations. An actally the .rap file > contains > only 1 2 or 3: > > &plot_rap nbnd_rap= 30, nks_rap= 1 / > 0.000000 0.000000 0.000000 T > > 1 1 2 2 2 2 2 > 2 3 > 3 > 1 1 3 3 1 1 1 > 1 2 > 2 > 2 2 1 1 3 3 1 > 1 2 > 2 > > So the two bands 11-12 at 6.803 are 1 -> Gamma_7, the two > bands 13-14 at > 6.816 are 3-> \Gamma_9 and > the two bands 15-16 7.015 are 1 -> \Gamma_7. The splitting is > 13 meV and > 0.199 meV in reasonable agreement with the APL that you > mention. > > It seems that you have the correct bands but bands.x is not > using C_6v > to classify the bands. > Which is the output of bands.x? > > Andrea > > > > > On Fri, 2009-04-03 at 11:10 +0800, ??? wrote: > > Dear pwscf users, > > I calculated band structure of AlN considering > spin-orbital > > interaction. Some published reports showed that considering > > spin-orbital interaction the top of valence band is split > into the > > Gamma7, Gamma9 and Gamma7 states by crystal field and > spin-orbital > > coupling (Appl. Phys. Lett. 83, 5163). However, my > calculated band > > structure is different from the published one. The > following is the > > input files: > > scf.in > > &control > > title = 2h_aln, > > prefix = '2h_band', > > calculation = 'scf' , > > restart_mode = 'from_scratch' , > > wf_collect = .false. , > > outdir = './' , > > wfcdir = './' , > > pseudo_dir = './' , > > tstress = .true. , > > tprnfor = .true. , > > wf_collect = .true. , > > / > > &SYSTEM > > ibrav = 4, > > celldm(1) = 5.904838149212, > > celldm(3) = 1.603024550651, > > nat = 4, > > ntyp = 2, > > ecutwfc = 80, > > nosym = .false. , > > lspinorb = .true., > > noncolin= .true., > > starting_magnetization=0.00, > > / > > &ELECTRONS > > electron_maxstep = 100, > > conv_thr = 1.D-12, > > / > > ATOMIC_SPECIES > > N 14.00700 N.rel-pbe-rrkjus.UPF > > Al 26.98200 Al.rel-pbe-rrkj.UPF > > ATOMIC_POSITIONS (crystal) > > N 0.333333333 0.666666667 0.379371803 > > N 0.666666667 0.333333333 0.879371803 > > Al 0.333333333 0.666666667 -0.002269507 > > Al 0.666666667 0.333333333 0.497730493 > > K_POINTS automatic > > 4 4 4 1 1 1 > > band.in > > &control > > title = 2h_aln, > > prefix = '2h_band', > > calculation = 'bands' , > > restart_mode = 'from_scratch' , > > wf_collect = .false. , > > outdir = './' , > > wfcdir = './' , > > pseudo_dir = './' , > > / > > &SYSTEM > > ibrav = 4, > > celldm(1) = 5.904838149212, > > celldm(3) = 1.603024550651, > > nat = 4, > > ntyp = 2, > > ecutwfc = 80, > > occupations='fixed', > > nbnd=30, > > lspinorb = .true., > > noncolin= .true., > > starting_magnetization=0.00, > > / > > &ELECTRONS > > electron_maxstep = 100, > > conv_thr = 1.D-12, > > / > > ATOMIC_SPECIES > > N 14.00700 N.rel-pbe-rrkjus.UPF > > Al 26.98200 Al.rel-pbe-rrkj.UPF > > ATOMIC_POSITIONS (crystal) > > N 0.333333333 0.666666667 0.379371803 > > N 0.666666667 0.333333333 0.879371803 > > Al 0.333333333 0.666666667 -0.002269507 > > Al 0.666666667 0.333333333 0.497730493 > > K_POINTS > > 1 > > 0.000000 0.000000 0.000000 1.00 > > > > bands.in for bands.x to get band symmetry information > > > > &inputpp > > prefix='2h_band' > > outdir='./' > > filband='spin.dat' > > lsigma(3)=.true. > > lsym=.true. > > / > > The calculated results of the band structure at Gamma point > is as > > following: > > spin.dat: > > &plot nbnd= 30, nks= 1 / > > 0.000000 0.000000 0.000000 > > -8.070 -8.070 -5.968 -5.968 1.092 1.092 6.154 > 6.154 > > 6.169 6.169 > > 6.803 6.803 6.816 6.816 7.015 7.015 11.136 > 11.136 > > 13.603 13.603 > > 17.513 17.513 18.094 18.094 18.118 18.118 19.967 > 19.967 > > 20.042 20.042 > > > > spin.dat.rap: > > &plot_rap nbnd_rap= 30, nks_rap= 1 / > > 0.000000 0.000000 0.000000 T > > 1 2 5 6 5 6 5 > 6 > > 3 4 > > 1 2 3 4 1 2 1 > 2 > > 5 6 > > 5 6 1 2 3 4 1 > 2 > > 5 6 > > > > My questions are: > > 1. Why the calculated top of valence bands (15th, and 16th ) > do not > > split as reported work (Appl. Phys. Lett.83,5163)? > > 2. In the spin.dat.rap file, what does the symbol "T" stand > for? And > > what does the "1 2 5 6 5 6 > 5 ..." > > mean? > > > > Thank you in advance! > > > > -- > > Y. C. Cheng > > Department of Physics > > Nanjing University > > Nanjing 210093 > > P. R. China > > Tel: 86-25-83592907 > > Email: yccheng.nju at gmail.com > > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > -- > Andrea Dal Corso Tel. 0039-040-3787428 > SISSA, Via Beirut 2/4 Fax. 0039-040-3787528 > 34014 Trieste (Italy) e-mail: dalcorso at sissa.it > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > -- > Y. C. Cheng > Department of Physics > Nanjing University > Nanjing 210093 > P. R. China > Tel: 86-25-83592907 > Email: yccheng.nju at gmail.com > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum -- Andrea Dal Corso Tel. 0039-040-3787428 SISSA, Via Beirut 2/4 Fax. 0039-040-3787528 34014 Trieste (Italy) e-mail: dalcorso at sissa.it
