Subject: ECP in GAMESS-US & GAUSSIAN92

From: Stefan Schulz <[email-masked]>
Date: Wed, 30 Aug 95 14:27:31 MESZ

Hi CCLers,

a few weeks back I posted a question concerning the use
of effective core potentials when migrating between
the ab initio programs GAMESS-US and GAUSSIAN92. 
I got quite a a lot of responses and would like to thank
all those poeple who took the time to help me. Here is a
summary of the answers I got:

*****************************************************************
In the GAMESS input :
 $CONTRL EXETYP=CHECK FRIEND=GAUSSIAN $END
Will give you an example gaussian input file in $JOB.dat, which (with a 
little modifications) will run perfectly on gaussian9x. 
Be sure to check the d5 <-> d6 thing. Check if they are d5 (or d6) 
for both programs, otherwise specify an extra keyword.
*****************************************************************
Hi there I have been using the 2 programs quite a bit lately and yes 
there is a simple command which you can use in GamessUS to prepare 
input for Gausian92. In the $CONTRL group if you include the keyword 
FRIEND=GAUSSIAN, then your run will be turned into a CHECK run 
(ie EXETYP=CHECK), and the input for G92 will be put in your PUN 
file for extraction. This should give you the correct input 
structure for the ECPs in G92. 
**********************************************************************
I've got the same problems just few days ago. I did not use d functions 
and the results in GAMESS-UK were more stable energetically than 
in GUASSIAN92. 
I'd appreciate a forward of any message that you get about this topic.
**********************************************************************
Hi Stefan,
hast Du dir die explizite formel von den ECP angeschaut? Ich weis 
nichtmehr wie es in den einzelnen Programmen Gaussian und Gamess
ist aber ich errinere mich an aehnliche probleme die ich vor ein paar 
jahren hatte. Ich denke der unteschied ist in dem Jacobi term vom 
ECP r^2, welcher in einem der programe explizit eingegeben werden mus 
nd in dem anderen nicht. Also schau ins Handbuch und eventuel muss du 
dan eine 2 won den n(i) Werten abziehen.
**********************************************************************

Thanks again to all those who answered. A few days after I posted
my question to the CCL I became aware of the program package MOLPRO94,
which as distinct from other commonly used quantum chemistry packages 
specializes on highly accurate computations for small molecules,
with extensive treatment of the electron correlation problem.

Since I am interested
in calculating ab initio potential surfaces for electronically 
excited states of medium sized molecules e.g. Na (NH3)_n n=1,2,...
I found the program package MOLPRO94 to be superior in this respect
to the programs GAMESS-US and GAUSSIAN92.

With this statement I really dont want to start any fundamental
discussion on which program performs better than the other, 
but rather use this opportunity to bring MOLPRO94 to the
attention of all those who might benefit from MOLPRO94.
Unfortunately MOLPRO94 is NOT FREE (No doubt that this is a
huge advantage of GAMESS-US). Information on MOLPRO94
is available at

http://tcibm.mols.sussex.ac.uk/molpro/molpro.html

Regards

Stefan

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|                              |            Stefan Schulz             |
| [email-masked]  | FU Berlin - Theoretical Chemistry    |
| Tel. ++49/30/838 5384 (2351) |            Takustrasse 3             |
| FAX. ++49/30/838 4792        |           D-14195 Berlin             |
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