Subject: dispersion and repulsion interaction

From: Pang Siu Kwong <[email-masked]>
Date: Tue, 6 Jan 1998 23:23:08 +0800 (HKT)

Hello!  The dispersion and repulsion interaction can be expressed by 

E=(-3/4)*N*A*B*C

N(packing number)=3.1416*{[r(solute)+r(solvent)]^2}/{[r(solvent)]^2}

A=a(solute)*a(solvent)

B=e(solvent)*e(solute)/[e(solvent)+e(solute)]

C=1/{[r(solvent)+r(solute)]^6}

a=mean (static) molecular polarizability

e=mean of molecular excitation energy

r=radius of molecule

Reference:
1. S. Miertus, V. Frecer, M. Majekova, Journal of Molecular 
Structure(Theochem), 179 (1988)353-356
2. V. Frecer, S. Miertus, M. Majekova, Journal of Moleuclar 
Structure(Theochem), 227 (1991)157-173

According to references, e=-2*E(HOMO).  Why?

How to determine the mean molecular polarizability through any theories? 
I know that Gaussian 94 has polar command and it gives the 6 values 
(tensors) of exact polarizability of molecule.  Is it possible to 
transform these values to mean molecular polarizability?

Thank you for your attention.

Patrick Pang