From Implicit to Explicit: An Interaction-Reorganization Approach to Molecular Solvation Energy

Accurate calculation of solvation energies has long fascinated
researchers, but complex interactions within bulk water molecules
pose significant challenges. Currently, molecular solvation energy
calculations are mostly based on implicit solvent approximations in
which the solvent molecules are treated as continuum dielectric media.
However, the implicit solvent approach is not ideal because it lacks
certain real solvation effects, such as that of the first solvation
shell, etc. Here, we propose an explicit solvent approach, interaction-reorganization
solvation (IRS) method, for molecular solvation energy calculations.
The IRS approach achieves predictive accuracy comparable to that of
the widely recognized solvation model based on the density (SMD) method
and is significantly more accurate than that of the Poisson–Boltzmann/generalized
Born surface area (PB/GBSA) methods. This is demonstrated in both
the correlation coefficient and the mean absolute error (MAE) with
respect to the experimental data. The IRS method is based on molecular
dynamics simulation in explicit solvent and does not need to solve
Poisson–Boltzmann or Schrödinger equations. On the other
hand, the accuracy of the IRS method does depend on the accuracy of
the molecular force field used in MD simulations. We expect that the
IRS method will be very useful for the solvation energy calculations
of molecules.