From chemistry-request@ccl.net Fri Apr 19 12:32:50 1991
Date: Fri, 19 Apr 91 12:01 EST
From: "Chuck Ulmer, University of Toledo" <ULMER%UTCHMA@uoft02.utoledo.edu>
Subject: G90 Question
To: chemistry@ccl.net
Status: R


  Gaussian 90 now has the ability to do direct SCF calculations.  I found
that using the direct SCF proceedure is almost three times as fast as 
indirect SCF on the CRAY for the system and basis set with which I am working.
My problem is that I cannot use direct SCF proceedures for MP3 single points
and I would like to know if I can speed the MP3 single point calculations by
setting the SCF convergence criteria lower (there are SCF=SinglePoint and
Conv=N keywords).  If this is possible, would this affect resulting energies,
would this speed calculations significantly, and how would I do this?

			Chuck Ulmer
			Department of Chemistry
			University of Toledo

			GRX0663@uoft02.utoledo.edu