Are you sure, your LDA+U calculations are done correctly ? You have to make spin polarized calculations with the correct magnetic order. Often a FM state is metallic, while the proper AFM state is insulating.
The full hybrid-DFT method will be available in the next release. However, this is an expensive method and you cannot apply it to large systems. At least you will need a powerful cluster with many nodes ... PS: Have you done mBJ calculations ? In our experience this is at least as accurate as hybrid DFT at a fraction of cpu-time when you need only the bands/DOS. It also works well for "correlated" electrons and in addition it does not have a parameter (like the alpha in hybrid-DFT or the U in LDA+U). Am 25.10.2011 12:14, schrieb David Tompsett: > Hi Shamik, > > DFT+U can sometimes give a reasonable description of materials with some > charge transfer (possibly also some Mott) insulating character eg. NiO. But > it seems that in your case > itinerant states are important to the band gap and in that case using Hybrid > functionals that include exchange between all states (including itinerant > ones) often helps eg. MnO. I > think a full hybrid functional set will come out in an upcoming version of > Wien2k? > > Some references: > Tran et al. > PHYSICAL REVIEW B83,235118 (2011) > > Best, > David. > > 2011/10/25 shamik chakrabarti <shamikphy at gmail.com <mailto:shamikphy at > gmail.com>> > > > Dear wien2k users, > > We all know that LSDA (or GGA)+U can be used > successfully for a Mott-Hubbard insulator. Anisimov et al. [PRL 99, 156404 > (2007)] have described > that for a charge transfer insulator we need to use LDA+DMFT for > modelling their band structure properly. Now my question is : > > (1) Is their any option in wien2k by which we can use LDA+DMFT? > > (2) In our calculation after applying GGA+U (U for d orbital of TM) we > saw that although there are a band gap between spin up & spin dn d DOS of > transition metal, there are > ligand (O p) DOS at Fermi Energy which is making our material metallic > while experimentally it is an insulator [conductivity ~ 10^(-7)]. Here should > we apply some value of U > (say 0.15 Ry) for O p orbital also? > > (3) Any other advice regarding to this problem will be highly appreciated. > > Thanks in advance. > > yours faithfully, > -- > Shamik Chakrabarti > Senior Research Fellow > Dept. of Physics & Meteorology > Material Processing & Solid State Ionics Lab > IIT Kharagpur > Kharagpur 721302 > INDIA > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at <mailto:Wien at > zeus.theochem.tuwien.ac.at> > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > > > > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien -- P.Blaha -------------------------------------------------------------------------- Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna Phone: +43-1-58801-15671 FAX: +43-1-58801-15698 Email: blaha at theochem.tuwien.ac.at WWW: http://info.tuwien.ac.at/theochem/ --------------------------------------------------------------------------
