HARTREE-FOCK 2ND DERIVATIVES AND ELECTRIC-FIELD PROPERTIES IN A SOLVENT REACTION FIELD - THEORY AND APPLICATION

A compact formalism for the second and third derivatives of the Hartree-Fock energy in the presence of an Onsager solvent reaction field is presented. All three standard algorithms (MO, AO, and direct) are extended to include the reaction field in a unified way. Predictions of the infrared spectrum of formaldehyde in a variety of solvents and of solvent-induced shifts in carbonyl stretching frequencies are presented along with the results of new measurements. As for the gas-phase case, analytical second derivatives are far more efficient than numerical ones. The reaction field provides very good predictions of solvent effects at negligible computational cost.