An efficient implementation for determining volume polarization in self-consistent reaction field theory

An efficient algorithm of the surface and volume polarization for electrostatics (SVPE) method in self-consistent reaction field (SCRF) theory, denoted by SV(1)PE, has been proposed to simulate direct volume polarization potential with a single layer of point charges outside the solute cavity while the indirect effects of volume polarization on surface polarization are still simulated with multiple layers of point charges. The free energies of solvation calculated using the SV(1)PE algorithm (implemented in GAUSSIAN03) reproduce the corresponding values calculated using the standard SVPE implementation within an error of only ∼0.1% when the solute cavity is defined by the standard 0.001e/ a03 solute charge isodensity contour. The SV(1)PE results are much less sensitive to the used cavity size in comparison with the well-established surface and simulated volume polarization for electrostatics [SS(V)PE] method which simulates volume polarization through an additional surface charge distribution on the cavity surface. The SCRF calculations using the SV(1)PE method are more efficient than those using the original SVPE method.