LDA+U could also be of help - and it's implemented in Siesta, as opposed to GW and hybrid functionals - but then U should be chosen carefully, such that the underlying physics comes out reliably.
Marcos On Tue, Jun 15, 2010 at 6:27 PM, Nichols A. Romero <[email protected]>wrote: > If your goal is to obtain a more accurate band gap, you will need DFT > with hybrid functions and or GW. > > On Tue, Jun 15, 2010 at 11:18 AM, Koch, Robert J <[email protected]> wrote: > > Hello All, > > > > I'd greatly appreciate any advice on the following: > > > > I'm trying to calculate the band gap of TIO2 (Rutile). I have attached > my fdf file, my pseudo .psf files as well as their input .inp files. > > > > When I run this and use the eig2dos utility to plot density of states, I > see a band gap of about 1.4 eV which is far too low (should be about 3.3 > eV). I'm aware that typically DFT calculations underestimate the band gap, > but this underestimation seems like a little much. Can anyone make any > recemendations as to how to improve my calculation? I'm quite stuck and not > sure how to proceed. > > > > Thanks in advance! > > Rob Koch > > > > > > -- > Nichols A. Romero, Ph.D. > Argonne Leadership Computing Facility > Argonne, IL 60490 > (630) 252-3441 (O) > (630) 470-0462 (C) >
