Subject: Compatability of Ab Initio results from different software Packages

From: [email-masked] (Andrew D. Fant)
Date: Wed, 8 Dec 93 10:28:53 -0500

Does anyone have any experience in how well Hartree-Fock energies calculated
by Gaussian 92 correlate with the same species calculated under GAMESS? 
The results are consistent with the trends I had been seeing under one program,
and they are also in agreement with the AM1 results I got from MOPAC.  
I know that given the same basis set and geometry the results OUGHT to be 
identical, but I am becoming more paranoid about numerical methods in general
lately, and I wanted to see if anyone had made a well-considered examination
of this question.

For what it's worth:  I did make a very small comparison (about 6 data-points)
between G92 and Spartan, and for HF and MP2, the energies of molecules 
geometry optimized by the respective programs were identical to the precision
of the platforms used.

Thanks for your input. 

Andy
Andrew D. Fant              Applications Analyst             [email-masked]
NCI-Frederick Cancer Research Facility        Biomedical Supercomuting Center
(301)846-5764             Me?!? Have an official NCI or Dyncorp Opinion? HAH!
"I'm just one too many mornings and a thousand miles behind" -- B. Dylan

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From: Szilagyi Robert <[email-masked]>
Date: Wed, 8 Dec 93 19:51:21 +0100

Dear Andy,

	I tested the g92 and the GAMESS packages on
tungsten carbene complexes, using ECPs.

	The GAMESS with SBK ECP is much better than
the G92 LANL1MB or LANL1DZ. Now I am going to test
the origin of the differences. They are due to the basis
set or the software. I will summarize the results on net
and to you of course.

Cheers,

			Rob