From chemistry-request@ccl.net Sun Oct  6 22:34:36 1991
Date:         Mon, 7 Oct 1991 10:12:42 SST
From: Heng Kek <CCECHK%NUSVM.BITNET@OHSTVMA.ACS.OHIO-STATE.EDU>
Subject:      Scratch space requirement for Gauss86
To: Computational Chem Grp at Ohio Supercom Ctr <CHEMISTRY@ccl.net>
Status: R

Hello,

I've just subscribed to this list/newsgroup.
I'm a computer programmer who installed the NEC version of Gaussian86
on the NEC SX-1A Supercomputer.  I'm now 'supporting' the software, but
I know next to nothing about computational chemistry.

The problem: G86 on the SX uses a tremendous amount of scratch filespace
             for the INTEGRAL and RWF (readwrite) files.  Both these
             files are 'direct access' files whose sizes need to be
             'allocated' before execution of the job.  And there is no
             'file expansion' facility.  Most of the time, users just
             allocate a large scratch space without really knowing how
             much they actually need.  If the space is insufficient,
             the program aborts (after much wasted cpu hrs).

Question: Is there a way to calculate beforehand, the size of the
          INTEGRAL and RWF files, given the input to the G86 program?

It would be most appreciated if anyone could provide some answers
or suggestions.  A user is currently trying to run a G86 job on the
SX with 450MBytes of integral file space and 700MBytes of readwrite
file space.  And this is NOT enough!!!  The program aborted due to
insufficient filespace for the readwrite file.

Another question is:  Is this sort of filesize for the integrals and
readwrite file typical??  I'm at a loss as to how to secure more disk
space.

Thanks in advance for any response.

Heng Kek
Analyst Programmer
Computer Centre
National University of Singapore
Acknowledge-To: <CCECHK@NUSVM>