<div>Dear dalcorso,</div>
<div> 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. </div>
<div><br> In addition, I want to know how to calculate the exciton energy level ? Is that possible in recent pwscf?<br></div>
<div class="gmail_quote">2009/4/3 Dal Corso Andrea <span dir="ltr"><<a href="mailto:dalcorso@sissa.it">dalcorso@sissa.it</a>></span><br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><br>On my PC, with your input I obtain:<br>
<div class="im"><br> &plot nbnd= 30, nks= 1 /<br> 0.000000 0.000000 0.000000<br> -8.070 -8.070 -5.968 -5.968 1.092 1.092 6.154 6.154 6.169<br>6.169<br></div> 6.802 6.802 6.816 6.816 7.016 7.016 11.136 11.136 13.603<br>
13.603<br> 17.514 17.514 18.094 18.094 18.118 18.118 19.967 19.967 20.042<br>20.042<br><br>That compare quite well with your bands:<br>
<div class="im"><br> &plot nbnd= 30, nks= 1 /<br> 0.000000 0.000000 0.000000<br> -8.070 -8.070 -5.968 -5.968 1.092 1.092 6.154 6.154 6.169<br>6.169<br> 6.803 6.803 6.816 6.816 7.015 7.015 11.136 11.136 13.603<br>
13.603<br> 17.513 17.513 18.094 18.094 18.118 18.118 19.967 19.967 20.042<br>20.042<br><br></div>The output of bands.x says that the code is using the group C_6v<br>to classify the bands<br><br> xk=( 0.00000, 0.00000, 0.00000 )<br>
<br> double point group C_6v (6mm)<br> there are 9 classes and 3 irreducible representations<br> the character table:<br><br> E -E C2 2C3 -2C3 2C6 -2C6 3s_v 3s_d<br> -C2 -3s_v -3s_d<br>
G_7 2.00 -2.00 0.00 1.00 -1.00 1.73 -1.73 0.00 0.00<br>G_8 2.00 -2.00 0.00 1.00 -1.00 -1.73 1.73 0.00 0.00<br>G_9 2.00 -2.00 0.00 -2.00 2.00 0.00 0.00 0.00 0.00<br><br>That has only three representations. An actally the .rap file contains<br>
only 1 2 or 3:<br>
<div class="im"><br> &plot_rap nbnd_rap= 30, nks_rap= 1 /<br> 0.000000 0.000000 0.000000 T<br></div> 1 1 2 2 2 2 2 2 3<br>3<br> 1 1 3 3 1 1 1 1 2<br>
2<br> 2 2 1 1 3 3 1 1 2<br>2<br><br>So the two bands 11-12 at 6.803 are 1 -> Gamma_7, the two bands 13-14 at<br>6.816 are 3-> \Gamma_9 and<br>the two bands 15-16 7.015 are 1 -> \Gamma_7. The splitting is 13 meV and<br>
0.199 meV in reasonable agreement with the APL that you mention.<br><br>It seems that you have the correct bands but bands.x is not using C_6v<br>to classify the bands.<br>Which is the output of bands.x?<br><br>Andrea<br>
<div>
<div></div>
<div class="h5"><br><br><br>On Fri, 2009-04-03 at 11:10 +0800, 程迎春 wrote:<br>> Dear pwscf users,<br>> I calculated band structure of AlN considering spin-orbital<br>> interaction. Some published reports showed that considering<br>
> spin-orbital interaction the top of valence band is split into the<br>> Gamma7, Gamma9 and Gamma7 states by crystal field and spin-orbital<br>> coupling (Appl. Phys. Lett. 83, 5163). However, my calculated band<br>
> structure is different from the published one. The following is the<br>> input files:<br>> <a href="http://scf.in/" target="_blank">scf.in</a><br>> &control<br>> title = 2h_aln,<br>
> prefix = '2h_band',<br>> calculation = 'scf' ,<br>> restart_mode = 'from_scratch' ,<br>> wf_collect = .false. ,<br>
> outdir = './' ,<br>> wfcdir = './' ,<br>> pseudo_dir = './' ,<br>> tstress = .true. ,<br>> tprnfor = .true. ,<br>
> wf_collect = .true. ,<br>> /<br>> &SYSTEM<br>> ibrav = 4,<br>> celldm(1) = 5.904838149212,<br>> celldm(3) = 1.603024550651,<br>
> nat = 4,<br>> ntyp = 2,<br>> ecutwfc = 80,<br>> nosym = .false. ,<br>> lspinorb = .true.,<br>
> noncolin= .true.,<br>> starting_magnetization=0.00,<br>> /<br>> &ELECTRONS<br>> electron_maxstep = 100,<br>> conv_thr = 1.D-12,<br>
> /<br>> ATOMIC_SPECIES<br>> N 14.00700 N.rel-pbe-rrkjus.UPF<br>> Al 26.98200 Al.rel-pbe-rrkj.UPF<br>> ATOMIC_POSITIONS (crystal)<br>> N 0.333333333 0.666666667 0.379371803<br>> N 0.666666667 0.333333333 0.879371803<br>
> Al 0.333333333 0.666666667 -0.002269507<br>> Al 0.666666667 0.333333333 0.497730493<br>> K_POINTS automatic<br>> 4 4 4 1 1 1<br>> <a href="http://band.in/" target="_blank">band.in</a><br>
> &control<br>> title = 2h_aln,<br>> prefix = '2h_band',<br>> calculation = 'bands' ,<br>> restart_mode = 'from_scratch' ,<br>
> wf_collect = .false. ,<br>> outdir = './' ,<br>> wfcdir = './' ,<br>> pseudo_dir = './' ,<br>> /<br>
> &SYSTEM<br>> ibrav = 4,<br>> celldm(1) = 5.904838149212,<br>> celldm(3) = 1.603024550651,<br>> nat = 4,<br>> ntyp = 2,<br>
> ecutwfc = 80,<br>> occupations='fixed',<br>> nbnd=30,<br>> lspinorb = .true.,<br>> noncolin= .true.,<br>
> starting_magnetization=0.00,<br>> /<br>> &ELECTRONS<br>> electron_maxstep = 100,<br>> conv_thr = 1.D-12,<br>> /<br>> ATOMIC_SPECIES<br>> N 14.00700 N.rel-pbe-rrkjus.UPF<br>
> Al 26.98200 Al.rel-pbe-rrkj.UPF<br>> ATOMIC_POSITIONS (crystal)<br>> N 0.333333333 0.666666667 0.379371803<br>> N 0.666666667 0.333333333 0.879371803<br>> Al 0.333333333 0.666666667 -0.002269507<br>
> Al 0.666666667 0.333333333 0.497730493<br>> K_POINTS<br>> 1<br>> 0.000000 0.000000 0.000000 1.00<br>><br>> <a href="http://bands.in/" target="_blank">bands.in</a> for bands.x to get band symmetry information<br>
><br>> &inputpp<br>> prefix='2h_band'<br>> outdir='./'<br>> filband='spin.dat'<br>> lsigma(3)=.true.<br>> lsym=.true.<br>> /<br>> The calculated results of the band structure at Gamma point is as<br>
> following:<br>> spin.dat:<br>> &plot nbnd= 30, nks= 1 /<br>> 0.000000 0.000000 0.000000<br>> -8.070 -8.070 -5.968 -5.968 1.092 1.092 6.154 6.154<br>> 6.169 6.169<br>
> 6.803 6.803 6.816 6.816 7.015 7.015 11.136 11.136<br>> 13.603 13.603<br>> 17.513 17.513 18.094 18.094 18.118 18.118 19.967 19.967<br>> 20.042 20.042<br>><br>> spin.dat.rap:<br>
> &plot_rap nbnd_rap= 30, nks_rap= 1 /<br>> 0.000000 0.000000 0.000000 T<br>> 1 2 5 6 5 6 5 6<br>> 3 4<br>> 1 2 3 4 1 2 1 2<br>
> 5 6<br>> 5 6 1 2 3 4 1 2<br>> 5 6<br>><br>> My questions are:<br>> 1. Why the calculated top of valence bands (15th, and 16th ) do not<br>> split as reported work (Appl. Phys. Lett.83,5163)?<br>
> 2. In the spin.dat.rap file, what does the symbol "T" stand for? And<br>> what does the "1 2 5 6 5 6 5 ..."<br>> mean?<br>><br>> Thank you in advance!<br>
><br>> --<br>> Y. C. Cheng<br>> Department of Physics<br>> Nanjing University<br>> Nanjing 210093<br>> P. R. China<br>> Tel: 86-25-83592907<br>> Email: <a href="mailto:yccheng.nju@gmail.com">yccheng.nju@gmail.com</a><br>
><br></div></div>
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</div><font color="#888888">--<br>Andrea Dal Corso Tel. 0039-040-3787428<br>SISSA, Via Beirut 2/4 Fax. 0039-040-3787528<br>34014 Trieste (Italy) e-mail: <a href="mailto:dalcorso@sissa.it">dalcorso@sissa.it</a><br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Y. C. Cheng<br>Department of Physics<br>Nanjing University<br>Nanjing 210093<br>P. R. China<br>Tel: 86-25-83592907<br>Email: <a href="mailto:yccheng.nju@gmail.com">yccheng.nju@gmail.com</a><br>