Subject: RE: gamess people play on the pc

From: "Slawomir Z. Janicki" <[email-masked]>
Date: Fri, 22 Dec 2000 20:30:47 -0600

I have been using PC-GAMESS for over two years now. It really enabled me to
run MCSCF calculations that were impossible to setup under the Unix version
of GAMESS due to disk space constrains. An AOINTS file that would not fit on
a 2GB partition under Unix was compressed to little over 200 MB on a PC.
I don't know of any program to transfer the guess orbitals (I think this is
what you are asking about) from Gaussian to GAMESS, but I am sure something
like this exists in this universe. Transferring the Cartesian coordinates is
a snap, but the z-matrices work somewhat differently in these programs. You
can't use the redundant coordinates in GAMESS like in Gaussian, I have not
investigated further. You have access to the same basis sets in Gaussian and
GAMESS, if something you need is not coded in, you can download your
preferred basis set off the Web and copy it to the input file.
In terms of resources I think that PC-GAMESS makes a better use of a PC than
Gaussian. I have used PC-GAMESS efficiently on PCs with four CPUs and I know
of installations that run distributed version of PC-GAMESS on as many as 512
CPUs. I don't know how the scaling compares to G98/Linda/Linux or
GAMESS/Beowulf/Linux, but on a single machine PC-GAMESS beats WinG98 any
time. I have mentioned the compression of the scratch files which really
reduces disk I/O for the price of minor increase of CPU usage. Overall, the
wall clock time is substantially reduced.
For operating system you really want WinNT4.0 or Win2000. Win98 or WinME
will give you a lot of grief :(. Depending on your finances/particular
calculations you may want to invest in a two-CPU machine (a PC with two
Celeron CPUs can be built for little money even though Intel maintains it
can't be done), EIDE-RAID controller (a $75 ATA/100 RAID controller + two
$100 7200 rpm 20GB ATA/100 disks make a very efficient subsystem) or DDR
memory.

Slawomir Janicki
[email-masked]

-----Original Message-----
From: Computational Chemistry List [mailto:[email-masked]]On
Behalf Of Shobe, Dave
Sent: Friday, December 22, 2000 10:20 AM
To: 'CCL'
Subject: CCL:gamess people play on the pc

I'm considering downloading Gamess-US for Windows (even though it will
probably take an entire day with my modem), because it has more
multireference options that Gaussian.

1. Have any of you done this, and would you recommend it?

2. Are there utilities that can transfer information (basis sets,
wavefunctions, etc.) between Gamess and Gaussian?

3. How do Gamess and Gaussian compare as regards time and resource use on a
PC?

--David

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