<html><body><div style="color:; background-color:; font-family:arial, helvetica, sans-serif;font-size:13px"><div><span>What I mean is if you suggest modified mBJ parameters (PRB 85, 155109) for semiconductors (gaps below 5 eV), what will be suitable for semiconductors whose band gaps are above 5 eV. I tried mBJ and got below 5eV. What is your opinion in this case?</span></div><div></div><div> </div><div>Yours sincerely</div><div>Jameson Maibam</div><div> <br> <div>----- Original Message -----<br> From: Peter Blaha <pblaha@theochem.tuwien.ac.at><br> To: A Mailing list for WIEN2k users <wien@zeus.theochem.tuwien.ac.at><br> Cc: <br> Sent: Saturday, 18 August 2012 10:42 PM<br> Subject: Re: [Wien] Okay to combine mBJ, spinorbit, and LDA+U?<br> <br>Read the paper<br><br>Am 18.08.2012 18:59, schrieb Jameson Maibam:<br>> Dear sir, please suggest suitable exchange correlation for ZrO2 in monoclinic structure. Its reported band gap using
GoWo is 5.34eV . My experimental groups got 5.5eV.<br>> Yours sincerely<br>> Jameson Maibam<br>><br>> ----- Original Message -----<br>> From: Peter Blaha <<a href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a>><br>> To: A Mailing list for WIEN2k users <<a href="mailto:wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:wien@zeus.theochem.tuwien.ac.at">wien@zeus.theochem.tuwien.ac.at</a>><br>> Cc:<br>> Sent: Saturday, 18 August 2012 10:15 PM<br>> Subject: Re: [Wien] Okay to combine mBJ, spinorbit, and LDA+U?<br>><br>> Yes, the Zn-3d states are very localized (like the 4f) and some U (much smaller than what you would use in GGA+U)<br>> will give you the experimental gap.<br>><br>> Alternatively you can use modified mBJ parameters (PRB 85, 155109) which are tailored more towards semiconductors<br>> (gaps below 5 eV) and bring the ZnO
gap above 3.2 eV.<br>><br>> Am 18.08.2012 18:27, schrieb Kamil Klier:<br>> > Thanks Fabien,<br>> ><br>> > Indeed the match between MBJLDA theory and experiment (Fig. 1 in the quoted paper) is excellent.<br>> ><br>> > However, the bandgap of ZnO is underpredicted by mBJ only, reading from Fig. 1 ca. 2.8 eV. This would render zinc oxide colored in the visible region, but pure ZnO is<br>> > white, in accord with experimental bandgap 3.2 - 3.4 eV. Moreover, the Zn3d_10 (filled) narrow band falls below the O2p valence band (from VB XPS) while a quick<br>> > calculation with MBJLDA results in blending of O2p and Zn3d. Is it possible that in the ZnO case the U (say U_eff = 0.46 Ry) would help a bit as follows: it would push the<br>> > Zn3d down and improve the bandgap - unless of course there are theoretical reasons why mBJ and U should be in
conflict. That does not seem to be the case, however, for 4f<br>> > orbitals.<br>> ><br>> > Best regards,<br>> ><br>> > Kamil Klier<br>> ><br>> > Quoting <a href="mailto:tran@theochem.tuwien.ac.at" ymailto="mailto:tran@theochem.tuwien.ac.at">tran@theochem.tuwien.ac.at</a> <mailto:<a href="mailto:tran@theochem.tuwien.ac.at" ymailto="mailto:tran@theochem.tuwien.ac.at">tran@theochem.tuwien.ac.at</a>>:<br>> ><br>> >> Yes, mBJ alone is already ok for NiO:<br>> >> <a href="http://prl.aps.org/abstract/PRL/v102/i22/e226401" target="_blank">http://prl.aps.org/abstract/PRL/v102/i22/e226401</a><br>> >> So, adding U is not a good idea.<br>> >><br>> >> On Sat, 18 Aug 2012, Kamil Klier wrote:<br>> >><br>> >>> The Wien example for NiO uses U_eff = 0.52 Ry
for the Ni3d orbitals.<br>> >>><br>> >>> Would that mean that using subsequent mBJ potential for 'improvement of<br>> >>> bandgap of NiO' is not appropriate or at least is an overkill?<br>> >>><br>> >>> Best regards,<br>> >>><br>> >>> Kamil Klier<br>> >>><br>> >>> Quoting Peter Blaha <<a href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a> <mailto:<a href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a>>>:<br>> >>><br>> >>> >mBJ+U is appropriate for 4f systems only (because mBJ is too weak to fully<br>> >>> >localize the 4f electrons). Do not use it for d-electrons.<br>>
>>> ><br>> >>> >mBJ is made to give a good bandstructure. We have evidence, that the<br>> >>> >resulting<br>> >>> >electron density is too ionic, thus a force optimization using MSR1a could<br>> >>> >be problematic (although it could be better than GGA in some cases (with 3d<br>> >>> >electrons - Jahn-Teller distortions).<br>> >>> >Eventually, MSR1a with the original BJ potential (c=1) is physically more<br>> >>> >justified, sind original BJ is an approximation to OEP (optimized effective<br>> >>> >potential),<br>> >>> >which should be close to the "exact local exchange-only" potential.<br>> >>> >(Note that an "exact exchange potential" + LDA-correlation can be much more<br>> >>> >wrong than plain LDA !!!!! for
certain cases, because we miss the error<br>> >>> >cancellation)<br>> >>> ><br>> >>> >before doing Spin-orbit calculations, I'd remove case.in0_ggr and use the<br>> >>> >case.grr file from the scf-mBJ calculation without SO. I do not trust<br>> >>> >the kinetic energy densities with SO.<br>> >>> ><br>> >>> ><br>> >>> >Am 16.08.2012 22:15, schrieb Laurence Marks:<br>> >>> > >If it is a decent insulator I would do LDA+U directly; often it<br>> >>> > >converges better and since the lattice parameter and forces change you<br>> >>> > >do not gain much by first doing LDA/GGA. Normally LDA+U is stable,<br>> >>> > >often more stable that LDA/GGA. Volume optimization should be done<br>>
>>> > >first, then min_lapw or MSR1a. Better is to do MSR1a or min_lapw at<br>> >>> > >each volume.<br>> >>> > ><br>> >>> > >Then add -so, mBJ as appropriate with the optimized positions.<br>> >>> > >However, I not sure if mBJ+U is appropriate (I doubt that it is). It<br>> >>> > >might be that LDA+U positions are a better approximation for mBJ, not<br>> >>> > >sure. One way is to minimize the forces with mBJ using MSR1a (not<br>> >>> > >min_lapw/PORT) and compare them to LDA+U. If they are the same then<br>> >>> > >you are in good shape, needs testing. Maybe someone has....<br>> >>> > ><br>> >>> > >N.B., it is completely fine to minimize positions in mBJ using MRS1a<br>> >>> >
>-- do not use min_lapw/PORT, it will not be correct. MSR1a does not<br>> >>> > >care that the energy is incorrect whereas min_lapw/PORT does.<br>> >>> > ><br>> >>> > >On Thu, Aug 16, 2012 at 2:44 PM, Jeff Spirko <<a href="mailto:spirko@lehigh.edu" ymailto="mailto:spirko@lehigh.edu">spirko@lehigh.edu</a> <mailto:<a href="mailto:spirko@lehigh.edu" ymailto="mailto:spirko@lehigh.edu">spirko@lehigh.edu</a>>> wrote:<br>> >>> > > >Is it okay to use spinorbit and LDA+U with mBJ?<br>> >>> > > ><br>> >>> > > >I would guess it is done like this:<br>> >>> > > > * Check that forces <10 mRy/au with plain LDA or GGA. Reduce via<br>> >>> > > > min_lapw.<br>> >>> > > > * Volume optimization (if desired) with plain
LDA or GGA to reduce<br>> >>> > > >absolute pressure.<br>> >>> > > > * Set up LDA+U (Sec 4.5.6) and use -orb flag from now on.<br>> >>> > > > * Need to converge LDA+U???<br>> >>> > > > * Follow mBJ instructions (Sec 4.5.9).<br>> >>> > > > * After mBJ+LDA+U is converged, follow spinorbit instructions (Sec<br>> >>> > > > 4.5.5).<br>> >>> > > > * For spinpolarized, check whether atoms became nonequivalent<br>> >>> > > >(affects case.inso, case.inorb,<br>> >>> > > > case.indmc, case.in1c, basically any input file with atom lists or<br>> >>> > > > indices)<br>> >>> > > > * touch .fulldiag (necessary because klist can change???)<br>> >>>
> > > * Do final run with -so -orb<br>> >>> > > ><br>> >>> > > >Best regards,<br>> >>> > > >--<br>> >>> > > >Jeff Spirko <a href="mailto:spirko@lehigh.edu" ymailto="mailto:spirko@lehigh.edu">spirko@lehigh.edu</a> <mailto:<a href="mailto:spirko@lehigh.edu" ymailto="mailto:spirko@lehigh.edu">spirko@lehigh.edu</a>> WD3V |=><br>> >>> > > ><br>> >>> > > >The study of non-linear physics is like the study of non-elephant<br>> >>> > > >biology.<br>> >>> > > >_______________________________________________<br>> >>> > > >Wien mailing list<br>> >>> > > ><a href="mailto:Wien@zeus.theochem.tuwien.ac.at"
ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br>> >>> > > ><a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>> >>> > ><br>> >>> > ><br>> >>> > ><br>> >>> ><br>> >>> >--<br>> >>> >-----------------------------------------<br>> >>> >Peter Blaha<br>> >>> >Inst. Materials Chemistry, TU Vienna<br>> >>> >Getreidemarkt 9, A-1060 Vienna, Austria<br>> >>> >Tel: +43-1-5880115671<br>> >>> >Fax:
+43-1-5880115698<br>> >>> >email: <a href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a> <mailto:<a href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a>><br>> >>> >-----------------------------------------<br>> >>> >_______________________________________________<br>> >>> >Wien mailing list<br>> >>> ><a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br>> >>> ><a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien"
target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>> >>> ><br>> >>><br>> >>><br>> >>><br>> >>> ----------------------------------------------------------------<br>> >>> This message was sent using IMP, the Internet Messaging Program.<br>> >>><br>> >>> _______________________________________________<br>> >>> Wien mailing list<br>> >>> <a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br>> >>> <a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien"
target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>> >>><br>> >> _______________________________________________<br>> >> Wien mailing list<br>> >> <a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br>> >> <a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>> >><br>> ><br>> ><br>> ><br>> > ----------------------------------------------------------------<br>> > This message was sent using IMP, the Internet Messaging Program.<br>> ><br>>
> _______________________________________________<br>> > Wien mailing list<br>> > <a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br>> > <a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>><br>> --<br>> -----------------------------------------<br>> Peter Blaha<br>> Inst. Materials Chemistry, TU Vienna<br>> Getreidemarkt 9, A-1060 Vienna, Austria<br>> Tel: +43-1-5880115671<br>> Fax: +43-1-5880115698<br>> email: <a href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a> <mailto:<a
href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a>><br>> -----------------------------------------<br>> _______________________________________________<br>> Wien mailing list<br>> <a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a> <mailto:<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a>><br>> <a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>><br>><br>> _______________________________________________<br>> Wien mailing list<br>> <a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br>> <a
href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>><br><br>-- <br>-----------------------------------------<br>Peter Blaha<br>Inst. Materials Chemistry, TU Vienna<br>Getreidemarkt 9, A-1060 Vienna, Austria<br>Tel: +43-1-5880115671<br>Fax: +43-1-5880115698<br>email: <a href="mailto:pblaha@theochem.tuwien.ac.at" ymailto="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a><br>-----------------------------------------<br>_______________________________________________<br>Wien mailing list<br><a href="mailto:Wien@zeus.theochem.tuwien.ac.at" ymailto="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br><a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br> </div> </div> </div></body></html>