From chemistry-request@ccl.net Sat Mar  7 02:51:54 1992
Date: Fri, 06 Mar 92 08:36:37 +0900
From: kddlab!vega.rc.m-kasei.co.jp!mei@uunet.UU.NET (Murakami Akinori)
Subject: Re: The future of ab initio
To: chemistry@ccl.net
Status: RO

Thanks to Gaussian inc. and IBM
>>     What would you do if you could ROUTINELY perform ab initio
>>     calculations (let say at the level of HF or HF/MP2) with 500
>>     contracted basis functions?  What kind of projects and
>>     applications would you run?
>>     Jan Labanowski
>>     Ohio Supercomputer Center
>>     
>> HF/6-31G* on C30H62 with no symmetry (574 basis functions) takes well under
>> a day in Gaussian 90 on an inexpensive workstation (RS/6000 model 530).
>> Shouldn't that question be "What applications do you do now that such
>> calculations have been possible for a couple of years?"
>> Michael Frisch
>> Gaussian, Inc.

We have following timing data of Gaussian90 on a IBM RS6000/550 which
is little bit expensive. IBM official Mflops is 25.
					unit[minute]
Molecule	Basis	SCF+grad
C10H8S2		132	28	
C14H12		150	29
C18H12S2	212	109

We are running 200 basis( 20~30 atom) calculation routinely.

But we have to use about 300~500 basis on Metal complex calculation in
our catalyst research.
We want to optimize 500 basis molecule, it will take about 1000 hour 
on 25 Mflops WS. One month for one calculation is not possible in our
research center.

					Akinori MURAKAMI
					Mitusbishi Kasei Corpration
					Yokohama, JAPAN