REACTION FIELD SPECTRAL SHIFTS WITH SEMIEMPIRICAL MOLECULAR-ORBITAL THEORY

A macroscopic solution polarization free-energy functional is combined with semiempirical molecular orbital theory to study shifts of electr onic absorption energies for several molecules in solution. The presen t method requires calculation of the induced electrostatic potential o n the van der Waals surface and this calculation is implemented in a n ew way. The combined method is tested by calculating absorption energy shifts for several molecules of standard interest. We find the physic ally reasonable result that there is a correlation between the absorpt ion energy shift and the magnitude of the dipole moments of the initia l and final states involved in the absorption transition. (C) 1997 Joh n Wiley & Sons, Inc.