  We present a multiwavelet-based implementation of a quantum/classical
polarizable continuum model. The solvent model uses a diffuse solute-solvent
boundary and a position-dependent permittivity, lifting the sharp-boundary
assumption underlying many existing continuum solvation models. We are able to
include both surface and volume polarization effects in the quantum/classical
coupling, with guaranteed precision, due to the adaptive refinement strategies
of our multiwavelet implementation. The model can account for complex solvent
environments and does not need a posteriori corrections for volume polarization
effects. We validate our results against a sharp-boundary continuum model and
find very good correlation of the polarization energies computed for the
Minnesota solvation database.
