Journal Article dielectric boundary force level-set method linear stability surface energy Boltzmann theory Charged molecules Ligands Nonpolar molecules Poisson Proteins Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Solute-solvent interfaces Solutions biomolecular modeling change of volume compact coupling interface method dielectric boundaries effective dielectric boundary force electrostatic energy electrostatic interactions ghost fluid method interface motion projection method solute-solvent interface solvation free energy solvent hydrodynamics the Stokes equation