Subject: Gaussian-98 efficiency for DFT calculations

From: "Ivan I. Oleinik" <[email-masked]>
Date: Mon, 22 Mar 1999 12:13:35 +0000 (GMT)

Hello,

I am a novice user of Gaussian and want to have a good advice from
experts on tuning Gaussian-98 options to get best performance in terms of
CPU time. 

Some specific information:

1. Molecular system:  medium-size hydrocarbon clusters (20-30 carbon
atoms) 

2. Method: DFT (standard LSDA + Becke-Perdew-Wang gradient corrections). 

3. Task: energy and forces with moderate accuracy.

4. System: SGI O2K machine with plenty of memory available. 

I can get trivial speedup by using several processors in parallel mode,
but I want to tune the execution on the level of single processor first.
Also the effect of the basis set size is also obvious and predictable.

Since I have to sample quite a large number of configurations studying
transition states, I have to count every CPU minute. But I according to my
little experience Gaussian is still slow as compared to MSI DMOL. 

I will summarize responses,

Ivan Oleinik.

------------------------------------------------------------------------
Ivan I. Oleinik                 E-mail : [email-masked]
Department of Materials
University of Oxford
Parks Road
Oxford OX1 3PH                     Tel : +44 (0)1865 283325
United Kingdom                     Fax : +44 (0)1865 273764 
------------------------------------------------------------------------