CCL:G: PCM and TD-DFT

["Tom de Greef" <t.f.a.d.greef],[tue.nl>]

 Sent to CCL by: "Tom de Greef" [t.f.a.d.greef|*|tue.nl]
 Dear all,
 I have a question about the use of TD-DFT calculations including PCM solvent
 effects using Gaussian 03. I have read in several papers that the best method to
 use the PCM solvent model in combination with TD-DFT is the non-equilibrium
 approach (when one is interested in the fast absorption processes). The solvent
 reaction field in the non-equilibrium regime depends in the PCM formalism on the
 dielectric constant at optical frequency (for CHCl3 this is 1.2). The default
 TD-DFT calculations in Gaussian03 assumes a non-equilibrium approach
 (NonEquilSolv is default). However, when I start a TD-DFT calculation in
 Gaussian03 for CHCl3 it automatically takes the value of the dielectric constant
 (for CHCl3 this is 4.9) for the calculation. Does this mean that I need to
 define the dielectric constant in an explicit way (by addition of the keyword:
 EPS=1.2)???
 With best regards,
 Tom