CCL:G: triplet TDDFT calculation



Michael,

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

Cheers,

Hillary

-------------------------------------------
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 michaelmorgan937%gmail.com <owner-chemistry^^^ccl.net> 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!
 
Michael