CCL:G: triplet TDDFT calculation


Could you please provide us with the text from your input file. It isn’t possible to inform on this matter otherwise.



Hillary Henthorn

M. D. Pluth Research Group
University of Oregon 
Department of Chemistry & Biochemistry
Office: 541.346.8711 
Cell: 503.709.6925

On Aug 16, 2016, at 8:42 PM, Michael Morgan <owner-chemistry^^^> wrote:

Dear All,
Standard TDDFT calculations calculate singlet->singlet excitations. In Gaussian, I can see that for each excitation, <S**2>=0.000.
While I calculate molecules like O2 which the ground state is triplet, I need calculate triplet->triplet excitations by assigning TD=triplet . 
In output, I found all kinds of <S**2> values (from 2 to 4). I am confused: for those are not close to 3, are they still spin-allowed therefore 
experimentally observable? Should I include them if I want to predict an absorption spectrum for the molecule?
Thank you very much!