Subject: Re:cal'n delta G of solvation

From: Jeffrey J Ayres <[email-masked]>
Date: Tue, 8 Oct 1996 03:29:04 +0000

The Spartan program, AM1 method will do delta G calculations for solvated
and unsolvated molecules.  The Spartan program may also do delta G energy of
solvation calculations at the PM3 level.  
As defined in the Hyperchem manual alpha is the polarizability of an atom
in the equations used in the 6-12 AtomVDWFormat entry set to SlaterKirkwood
used in describing van der Waals interactions
Bij=   (C)(alpha i)(alpha j)
         ________________
       (  alpha i)^1/2       ( alpha j)^1/2
       (  _____)       +     (_____)
       (     N i  )              (  N j  )

Aij=1/2Bij(Ri+Rj)^6
Aij and Bij are parameters of interaction
Ni=the effective number of valence electrons for an atom of type i
Ri=the van der Waals radius  of an atom of type i
C is a constant which combines the permittivity of free space (epsilon
knot), the charge of an electron (e), the mass of an electron (m) and
Planck's constant
C=                3eh
     _____________________
     4((pi)(epsilon knot)(m))^1/2

The  6-12AtomVDW Format entry set to SlaterKirkwood is used in Molecular
Mechanics methods.

The calculation of the value of  mu pertains to the dipole vector of the atom.