The importance of excluded solvent volume effects in computing hydration free energies.

摘要: Continuum dielectric methods such as the Born equation have been widely used to compute electrostatic component of solvation free energy, DeltaG(solv)(elec), because they do not need include solvent molecules explicitly and are thus far less costly compared molecular simulations. All these can be derived from Gauss Law Maxwell's equations, which yields an analytical solution for DeltaG(Born), when solute is spherical. However, in assumed a structureless continuum, whereas reality, near-solute highly structured unlike far-solute bulk solvent. Since we recently reformulated equations incorporate structure by considering excluded volume effects, it this work derive hydration energy ion. In contrast continuum models, assume that normalized induced electric dipole density P(n) constant, mimics observed The formula ionic shows radius, has adjustable parameter fit experimental energies, no longer ill defined but related radius polarizability water molecule, number, first peak position solute-solvent radial distribution function. resulting DeltaG(solv)(elec) values shown close respective numbers.