Well ... for sure there are lots of studies using DFT to calculate such properties. Another question is whether this results are meaningful or not... and that is controversial.
The problem is that some people don´t see much meaning on conduction bands calculated with single reference methods, since their eigenvalues are not really taken into account while diagonalizing the system's Hamiltonian. Another issue is the meaning of the Kohn-Sham orbitals themselves. It has been demonstrated - at least for molecules - that they do have the same simmetry properties as HF orbitals and that the also agree with the Koopman's theorem after rescalling. I also know that there are some recent works (see the link) on a DFT version of the Koopman's theorem, but in order to verify that you have to go beyond standard DFT: http://www.ingentaconnect.com/content/nrc/cjc/2009/00000087/00000010/art00014 Given that, you can calculate the optical properties of any material with DFT if you think that the conduction bands are meaningful ... but you are going to have a hard time if your referee think it is not true. Cheers NH 2011/3/4 Gregorio García Moreno <[email protected]> > Hi > I have never used SIESTA to calculate optical properties, but recently have > accepted a propious work where electronic structure of conducting polymers: > band diagrams, bandgap, bandwiths, effective mass, ect. All these properties > are related with optical properties, and the reviewers didn't say anything > about the methodology (DFT and SIESTA) > I can't help you, but you can look for other works where DFT implemented in > siesta is used to assess optical properties. > Besides, respect to DFT there are a lot of works which use DFT to calculate > optical properties of photovoltaic cells, oleds, synthetized dyes, etc. > I think that that all works of nowadays on optical properties use DFT. > I know that Carlo Adamo's group are working in the development of new > fuctionals to assess optical properties. > Unfortunately, all these functional are not implemented in SIESTA. > On the other hand, there are a lot of scale factors in bibliography to > correct theoretical values in concordance with experimental ones. > > Sorry, I can't help more > > Gregorio > > El 3/4/2011 9:16 AM, caqhero escribió: > > Recently, I used the siesta to calculate the optical properties of CNTs. > The reviewer ask the method I used. and he say that the Ground-state DFT can > not accurately describe optical properties. I confuse the method for optical > calculation in siesta. can any body tell me the details ? how can I reply > the reviewer ? is it reliable using the siesta to calculate the optical > properties ? any suggestion is appreciated ! thank you ! > > > > > >
