From chm6@midway.uchicago.edu  Sun Nov 15 18:32:51 1992
Date: Mon, 16 Nov 92 00:32:51 CST
From: "charles martin" <chm6@midway.uchicago.edu>
Message-Id: <9211160632.AA05369@midway.uchicago.edu>
To: CHEMISTRY@ccl.net
Subject: deficiencies in semi-empirical methods


Hello netters,

I am hoping that some of you can help me out.  I am trying to find
specific references describing in detail deficiencies in semi-empirical 
methods as well as attempts and/or successful improvements.

Here is a list of topics which I am trying to find out about:


1) The use of different parameterization schemes for specific molecules
 or classes of molecules to treat different properties 
 (e.g. excitation energies, ionization potentials, 
 heats of atomization/formation, etc.) 

2) Specific examples of calculations demonstrating where semi-empirical
 methods fail but ab initio methods succeed (and vice versa).

3) Ab Initio calculations of semi-empirical parameters.
  (and/or)
 Models which explicitly describe how correlation contributions enter
 into the semi-empirical parameters.

4) Inclusion of Rydberg orbitals, d orbitals, etc. into
 semi-empirical valence spaces.

I realize that there are a lot of works which describe new and improved
methods (I would be very happy to read any of these sent my way).
What I am particular looking for, again, however, are documented 
examples detailing the deficiencies of semi-empirical methods.

I will summarize the information I receive and provide it via email
to any interested parties.

Thank you very much in advance:)

Charles H. Martin
The University of Chicago
Department of Chemistry and the James Franck Institute
chm6@quads.uchicago.edu