Re: CCL:absorbance spectra or colored compound prediction

Dear all,
 S. I. Gorelsky and A. B. P. Lever used ZINDO and TD-DFT a lot for calculating
 absorption spectra of (charged) transition metal complexes. There are numerous
 papers where they used both techniques, but this one might be a good start:
 J Organomet Chem, 635 (2001) 187-196.
 The conclusions are that both methods yield similar results, most interestingly,
 that this also applies to the calculated MOs (Kohn-Sham-orbitals vs.
 semiempirical ZINDO/s-MOs). I do not know too much about DFT/TD-DFT, but to my
 knowledge prior to that publication, DFT-theory only gives something physically
 meaningful and interpretable for the overall-electron density (and all
 quantities derivable from that), but not for "single
 electron"-wavefunctions
 (=MOs). However, I might be wrong.
 Best wishes,
 Andreas
 Geoff Hutchison wrote:
 >
 > On Jun 13, 2005, at 2:07 AM, Rey Puiggros Oscar wrote:
 >
 >> depending on the size of your system my choice would be Time
 >> Dependent Density Functional Methods or ZINDO/S. The first one is
 >> quite accurate but it is more expensive, while ZINDO/S is semi-
 >> empirical and faster but with lower accuracy.
 >
 >
 > I'm not sure I'd completely agree with that. For neutral organic
 > molecules, I think ZINDO/S does almost as well as TDDFT. Both do well
 > with low-lying excited states.
 >
 > e.g.
 > Hutchison, G. R.; et. al. J. Phys. Chem. A 2002, 106, 10596.
 > Fabian, J. Theor. Chem. Acc. 2001, 106, 199.
 >
 > I'm sure there are similar "benchmark" studies too. (Although if
 anyone
 > has similar comparative experiment vs. computed papers for  charged
 > organic species, I'd be grateful for references.)
 >
 > -Geoff
 --
 Andreas Serr
 Biological Soft-Matter Theory
 Department fuer Physik - Ludwig-Maximilians-Universitaet
 Theresienstr. 37, D-80333 Munich, Germany
 tel: +49-(0)89-2180-4559 / fax: +49-(0)89-2180-4517
 room no: 302 / e-mail: serr :a: theorie.physik.uni-muenchen.de
 http://www.theorie.physik.uni-muenchen.de/biophysics/