D. Qiu et al., THE GB SA CONTINUUM MODEL FOR SOLVATION - A FAST ANALYTICAL METHOD FOR THE CALCULATION OF APPROXIMATE BORN RADII/, The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 101(16), 1997, pp. 3005-3014
Atomic Born radii (alpha) are used in the generalized Born (GB) equati
on to calculate approximations to the electrical polarization componen
t (G(pol)) of solvation free energy. We present here a simple analytic
al formula for calculating Born radii rapidly and with useful accuracy
. The new function is based on an atomic pairwise r(ij)(-4) treatment
and contains several empirically determined parameters that were estab
lished by optimization against a data set of >10 000 accurate Born rad
ii computed numerically using the Poisson equation on a diverse group
of organic molecules, molecular complexes, oligopeptides, and a small
protein. Coupling this new Born radius calculation with the previously
described GB/SA solvation treatment provides a fully analytical solva
tion model that is computationally efficient in comparison with tradit
ional molecular solvent models and also affords first and second deriv
atives. Tests with the GB/SA model and Born radii calculated with our
new analytical function and with the accurate but more time-consuming
Poisson-Boltzmann methods indicate that comparable free energies of so
lvent like dielectric polarization can be obtained using either method
and that the resulting GB/SA solvation free energies compare well wit
h the experimental results on small molecules in water.