Author Topic: COSMO and TDDFT  (Read 4623 times)

oana

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COSMO and TDDFT
« on: February 19, 2008, 11:40:09 AM »
Hi,

I am using TDDFT with COSMO to interpret the absorption spectra in solvents of
different polarities of some indolizine compounds.

The problem that there is almost NO difference in absorption intensities (osc. strength.)
depending on the solvent. However, experimental spectra show a very large change
in absorbance when comparing polar and non-polar solvents.

Is this problem known? Can anybody offer an explanation?

Could it be a similar cause as in the ADF software, see below.

ADF manual is say related to their own COSMO implementation:

" Yes, it is be possible to combine COSMO and TDDFT. The usually major effect
(modified zeroth order KS orbitals and orbital energies) is then included.

However, COSMO should also modify the first-order change in the KS potential.
This effect has not yet been implemented and will certainly be important in case
of a high value for the dielectric constant."
 

Thanks in advance,
Oana Cramariuc