Excited state polarizabilities in solution obtained by cubic response theory:: Calculations on para-, ortho-, and meta-nitroaniline

We show that response theory implemented with a self-consistent reaction held theory model is a viable approach to simulate excited state polarizabilities of molecules in solution. The excited state polarizabilities are in this approach given by the double residue of the ground state cubic response functions, accounting for both equilibrium and nonequilibrium contributions to the interaction with the outer medium. The effects of the inertial polarization of the solvent on the polarizabilities of the solutes are shown to strongly depend on the solvent configuration, whether the solvent is in equilibrium or in nonequilibrium with the charge distribution of the investigated compound. The inertial polarization vector in the nonequilibrium solvent configuration represents the equilibrated solvent configuration when solvating the ground state of the solute. This inertial polarization vector is not in equilibrium with any of the excited states and therefore one observes a rather different behavior between nonequilibrium and equilibrium solvent descriptions of the solute. Illustrative calculations are presented for para-, meta-, and ortho-nitroanilines in gas and solution phases. Results have been compared with experimental data where available. (C) 1998 American Institute of Physics. [S0021-9606(98)01639-0].