Gaussina 9x memory/disk requirements

From: Kurt.Hillig - at - um.cc.umich.edu
Subject: Gaussina 9x memory/disk requirements
Date: Tue, 27 Apr 93 11:07:18 EDT

 I've often seen the claim that memory (for in-core) or disk space
 needed by Gaussian 9x scales as N^4/4 (SCF).  I expect a first-order
 approximation to the memory needs can be given by M = A + B N^4,
 where A is the "overhead" and B is a scale factor (words per
 integral?).
 I've occasionally seen some very rough estimates - for example today,
 the claim (paraphrased) 100 basis functions:100 MWords, 200 BF's:200 MW,
 300 BF's:>1GW - but it's hard to fit this to a fourth-order polynomial
 with any accuracy (;-) and it doesn't match M = N^4/4 (i.e. A=0, B=.25)
 particularly well.
 Can anyone supply more accurate numbers so I can better advise my users?
     Dr. Kurt Hillig
    Dept. of Chemistry      I always tell the     khillig - at - umich.edu
  University of Michigan     absolute truth    Telephone (313)747-2867
 Ann Arbor, MI  48109-1055    as I see it.    hillig - at - chem.lsa.umich.edu