The combined multiconfigurational self-consistent-field/molecular mechanics wave function approach

We present theory and implementation for a new approach for studying solvent effects: the multiconfigurational self-consistent-field/molecular mechanics method. With this method it is possible to describe ground, excited, and ionized states of molecules in solution. The approach is tested by investigating the effect of solvent on ${\mathrm{H}}_{\mathrm{2}}\mathrm{O}$ in aqueous solution. For the calculated energies we find that polarization effects are significant.