<html><body><div style="color:; background-color:; font-family:arial, helvetica, sans-serif;font-size:13px"><div><span>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.</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 10:15 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>:<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>>:<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>> 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> 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><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><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>>>> ----------------------------------------------------------------<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><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><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><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><br>-----------------------------------------<br>_______________________________________________<br>Wien mailing list<br><a href="mailto:Wien@zeus.theochem.tuwien.ac.at"
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