Are Time-dependent DFT calculations compatible with the COSMO model?
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.