Solvent-excluded molecular volume

Definition:

V_p - volume of internal polyhedron

- volume pieces between the center of an atom and 
              the convex face of the solvent-accessible surface

 - volume of saddle pieces

- volume of concave pieces

V_ac, V_nc - cusp volume pieces

Reference:

1. M. L. Connolly, J. Am. Chem. Soc., 1985, 107, 1118-1124.