Subject: deformation density calculations

From: [email-masked]
Date: Wed, 1 Mar 1995 13:34:26 MST

Hi folks,

I am attempting to calculate the theoretical deformation densities of a group 
of molecules.  The deformation density is the difference between the total 
electron density of a molecule (calculated or experimental) and the electron 
density of "neutral spherical unperturbed atoms" superimposed at the same 
nuclear positions.  I am currently using Fenske-Hall MO calculations to define 
the molecule and the associated program MOPLOT to subtract the unperturbed 
density.  I have been finding that the Fenske-Hall method overestimates the 
density in lone pair regions and underestimates that in bonding regions.  This 
problem has been reported in the literature previously for restricted basis 
sets.  The solution has been to move to Ab Initio methods using extended basis 
sets.

So, I am looking for a package that will allow me to calculate deformation 
densities. Gaussian92 is available in our department, but I have been unable to 
define/obtain the "neutral unperturbed atom density". (I am a beginner using Ab 
Initio calculations.)  Does anyone know how this may be done in G92? I'd also 
be interested in any other packages that would allow me to calculate 
deformation densities.

Thanks for your time.

			---Mike Carducci
			Department of Chemistry
			University of Arizona
			[email-masked]