Dear Andrea, <div><br></div><div>No, I have no inversion symmetry in my system. So I expect the bands at k,up and -k,dn (up,dn:spin) to be the same due to the time reversal symmetry. Let me quote part of my results for spin component 1 (Mx):</div>
<div><br></div><div>at k</div><div><div> 0.013 -0.007 0.108 -0.114 -0.108 0.102 -0.047 0.032 -0.073 0.094</div><div> 0.250 -0.250 -0.250 0.250 -0.250 0.250 0.243 -0.246 0.085 -0.058</div><div>
-0.050 -0.015 -0.058 0.072 0.048 -0.015 -0.075 0.072 0.129 -0.110</div><div> -0.237 0.215 -0.087 0.085 -0.245 0.248 -0.243 0.244 0.249 -0.249</div></div><div><br></div><div>at -k</div><div><div>
-0.013 0.007 0.114 -0.108 -0.102 0.108 -0.032 0.047 0.073 -0.094</div><div> 0.250 -0.250 -0.250 0.250 -0.250 0.250 0.246 -0.243 0.058 -0.085</div><div> 0.015 0.050 -0.072 0.058 0.015 -0.048 -0.072 0.075 0.110 -0.129</div>
<div> -0.215 0.237 -0.085 0.087 -0.248 0.245 -0.244 0.243 0.249 -0.249</div></div><div><br></div><div>I am in particular interested in band #29. As you can see for both k and -k they are positive (0.129, 0.110). However, I just found the eigen-energies corresponding to band #29 and #30 are just reversed between k and -k:</div>
<div><br></div><div>at k</div><div><div> -18.403 -18.403 -18.394 -18.393 -15.427 -15.426 -15.415 -15.415 -15.401 -15.401</div><div> -6.240 -6.236 -5.303 -5.292 -3.535 -3.529 1.548 1.611 2.796 2.864</div><div>
3.577 3.637 3.964 4.063 4.482 4.540 4.800 4.833 7.649 7.776</div><div> 8.465 8.587 9.257 9.264 10.863 10.866 12.514 12.537 13.804 13.824</div><div>at -k</div><div> -18.403 -18.403 -18.393 -18.394 -15.426 -15.427 -15.415 -15.415 -15.401 -15.401</div>
<div> -6.236 -6.240 -5.292 -5.303 -3.529 -3.535 1.611 1.548 2.864 2.796</div><div> 3.637 3.577 4.063 3.964 4.540 4.482 4.833 4.800 7.776 7.649</div><div> 8.587 8.465 9.264 9.257 10.866 10.863 12.537 12.514 13.824 13.804</div>
</div><div> </div><div>As you see, in the former the respective energies of bands #29 and #30 are 7.649 and 7.776. But for -k, they become 7.776 7.649. Apparently the ordering of bands at k and -k are not the same. So I guess my mistake was to compare Mx at k with Mx at -k for the same band numbers. Do you have any suggestion?</div>
<div><br></div><div>Thanks,</div><div> </div><div><br></div><div> </div><div><div class="gmail_quote">On Mon, Jan 17, 2011 at 10:08 PM, Andrea Dal Corso <span dir="ltr"><<a href="mailto:dalcorso@sissa.it">dalcorso@sissa.it</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Please provide more details. Is there inversion symmetry in your system?<br>
<font color="#888888"><br>
Andrea<br>
</font><div><div></div><div class="h5"><br>
On Mon, 2011-01-17 at 21:13 +0900, soroush pakseresht wrote:<br>
> Dear Andrea and Gabriele,<br>
><br>
><br>
> First, let me thank both of you for your valuable comments and<br>
> feedbacks.<br>
> As suggested by Andrea, I used bands.x with lsigma=.true. . It seems<br>
> to be working. Now I can see the results for Mx, My and Mz components<br>
> of magnetization. However, something seems to be wrong. The<br>
> magnetization which I get for the same band but at k and -k are<br>
> exactly the same. Due to the strong spin-orbit coupling, I am<br>
> expecting that the direction of magnetization at k becomes opposite to<br>
> that at -k. Is it due to some symmetry constraints, which I might have<br>
> not turned off during the SCF and NSCF calculations? Any idea?<br>
><br>
><br>
> Looking forward for your response,<br>
> Saeed<br>
><br>
> On Mon, Jan 17, 2011 at 7:55 PM, Andrea Dal Corso <<a href="mailto:dalcorso@sissa.it">dalcorso@sissa.it</a>><br>
> wrote:<br>
><br>
> On Mon, 2011-01-17 at 11:48 +0100, Gabriele Sclauzero wrote:<br>
> > Hi Soroush<br>
> ><br>
> > On 01/15/2011 02:50 PM, soroush pakseresht wrote:<br>
> > > Hi everybody,<br>
> > ><br>
> > ><br>
> > > Can anybody tell me how I can calculate the magnetization<br>
> > > M=M(Mx,My,Mz) for a system with spin-orbit coupling.<br>
> ><br>
> > Usually the three components of the total non-collinear<br>
> magnetization<br>
> > are printed at the end of the calculation, e.g.<br>
> ><br>
> > The total energy is the sum of the following terms:<br>
> ><br>
> > one-electron contribution = -90.33299784 Ry<br>
> > hartree contribution = 49.63924278 Ry<br>
> > xc contribution = -28.28794844 Ry<br>
> > ewald contribution = -0.25003496 Ry<br>
> > smearing contrib. (-TS) = -0.00000505 Ry<br>
> ><br>
> > total magnetization = 0.00 0.00 0.11<br>
> Bohr<br>
> > mag/cell<br>
> > absolute magnetization = 0.11 Bohr mag/cell<br>
> ><br>
> ><br>
> ><br>
> > > I'd like to know the total value of Mx, My, Mz for each<br>
> band at a<br>
> > > given kpoint.<br>
> > ><br>
> ><br>
><br>
><br>
> You can use the program bands.x with the flag lsigma=.true. .<br>
> Please check INPUT_BANDS for more info.<br>
><br>
> HTH<br>
><br>
> Andrea<br>
><br>
><br>
><br>
> > What you're asking for is somehow the magnetization carried<br>
> by the<br>
> > individual KS eigenstates. I think that for this you'll have<br>
> to modify<br>
> > the PWscf or PostProc code. For instance you could start<br>
> from pp.x and<br>
> > modify the option plot_num=7 by performing the integral of<br>
> the<br>
> > resulting spin-density over the whole unit cell (should be<br>
> the sum<br>
> > over the FFT components, perhaps multiplied by some<br>
> normalization<br>
> > factor).<br>
> > Maybe it's easier to implement this directly in PWscf. At<br>
> the moment<br>
> > the code first computes the total spin-density (which is the<br>
> sum over<br>
> > bands and k-points of the individual KS densities) in<br>
> sum_band.f90<br>
> > (search for 'domag') and then the magnetization by<br>
> integrating the<br>
> > components of the spin-density (see compute_magnetization in<br>
> > PW/electrons.f90). You can modify sum_band.f90 by adding a<br>
> call to a<br>
> > function analogous to compute_magnetization but for each<br>
> single KS<br>
> > state.<br>
> ><br>
> ><br>
> > HTH<br>
> ><br>
> > GS<br>
> ><br>
> > ><br>
> > ><br>
> > > Thanks<br>
> > ><br>
> > > --<br>
> > > Soroush Pakseresht<br>
> > > Advanced Science Institute (RIKEN)<br>
> > > Saitama-Japan<br>
> > ><br>
> > ><br>
> > ><br>
> > > _______________________________________________<br>
> > > Pw_forum mailing list<br>
> > > <a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br>
> > > <a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/mailman/listinfo/pw_forum</a><br>
> > ><br>
> ><br>
> ><br>
> > --<br>
> ><br>
> > Gabriele Sclauzero, EPFL SB ITP CSEA<br>
> > PH H2 462, Station 3, CH-1015 Lausanne<br>
> > _______________________________________________<br>
> > Pw_forum mailing list<br>
> > <a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br>
> > <a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/mailman/listinfo/pw_forum</a><br>
> --<br>
><br>
> Andrea Dal Corso Tel. 0039-040-3787428<br>
> SISSA, Via Bonomea 265 Fax. 0039-040-3787249<br>
> I-34136 Trieste (Italy) e-mail: <a href="mailto:dalcorso@sissa.it">dalcorso@sissa.it</a><br>
><br>
><br>
><br>
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><br>
><br>
><br>
><br>
> --<br>
> Soroush Pakseresht<br>
> Advanced Science Institute (RIKEN)<br>
> Saitama-Japan<br>
><br>
><br>
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--<br>
Andrea Dal Corso Tel. 0039-040-3787428<br>
SISSA, Via Bonomea 265 Fax. 0039-040-3787249<br>
I-34136 Trieste (Italy) e-mail: <a href="mailto:dalcorso@sissa.it">dalcorso@sissa.it</a><br>
<br>
<br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Soroush Pakseresht<div>Advanced Science Institute (RIKEN)</div><div>Saitama-Japan</div><br>
</div>