  In the given paper we describe methods finding analytical gradients
(derivatives) of solvation energy over atomic coordinates. It is made both for
not polar energy and for the polar energy found by methods PCM, COSMO and SGB.
These gradients are searched with use of analytical gradients of parameters
(coordinates, normal vectors and squares) the surface meshes. The surface
meshes are located on both the optimal smooth molecular surfaces: solvent
excluded surface (SES) and surface solvent accessible surface (SAS) received
from SES. These surfaces are found by methods of primary and secondary rolling
according to the algorithm described in the previous papers of the series.
