Subject: Comparison of current DFT codes?

From: [email-masked] (Alan Arnold)
Date: Wed, 3 Nov 1993 15:50:38 +1100

Thanks to Andrew D Allen <[email-masked]> for his recent (4 Oct 1993)
summary of references to DFT techniques, but I was sorry to see the DFT
discussion die out so suddenly. I've discovered that one could not do much
better than to look through the excellent book by J.K. Labanowski and
J.W.Andzelm: "Density Functional Methods in Chemistry"1991. XII, 443 pp. 68
figs to get some feel for the applications that were being tackled a few
years ago.

At this moment, I'm trying to make a decision on which code to use to
investigate the effects of conformational energetics on redox and
electronic spectroscopic properties of a series of polynuclear Co(III)
complexes that we have synthesised in our labs.  Because we have some
investment in Biosym's molecular modelling package InsightII/Discover, I'm
tempted to try their DFT package DMol, but the $ cost is high.  

So, I would like to hear some very pragmatic, perhaps contentious ;-)
comparisons of the currently avaliable DFT codes in this forum.  Surely the
expertise is here, probably lurking in the background, to provide such
up-to-date information.

Are there more capable, publicly-available packages available (perhaps not
with such completely integrated graphics as DMol), particularly suited for
TM-complexes?

To set the ball rolling, which is better value: Dmol or DGauss or Dxxxx???

Please reply to the list rather than by email to me.  I may be wrong, but I
suspect that other readers would be interested in this information.
----
Alan Arnold                          |  e-mail: [email-masked]
Chem. Department,University College  |  voice : +61 6 268 8080
Australian Defence Force Academy     |  fax   : +61 6 268 8002
CANBERRA  ACT 2601 Australia         |

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From: [email-masked] (David Case)
Date: Wed, 3 Nov 93 07:41:35 PST

> complexes that we have synthesised in our labs. 

We have been please with the "ADF" (Amsterdam Density Functional) codes in
our calculations on polynuclear iron-sulfur, iron-oxo and manganese-oxo
clusters.  For an overview of this work, see Adv. Inorg. Chem. 38:423-470 
(1992).  ADF is supplied in source code format, so you can examine the
details of the calculations and make modifications if you wish.  ADF uses
Slater type orbital basis sets, which appear to do a good job, and the
overall approach has been widely tested -- see e.g. the review by Tom 
Ziegler,  Chem. Rev. 91:651-667 (1991).

The ADF programs can place some severe constraints on your cpu and
available disk space.  We have also made considerable use of DGauss for
transition-metal complexes, and are generally pleased with it, although
we have not yet figured out how to carry out broken symmetry
calculations on multi-metal systems with it.  DGauss is a part of a
package called Unichem, which is distributed by Cray Research and by
MSI.  It uses Gaussian basis sets. There is a consortium which helps to
support its development;  members of the consortium receive 
updates about a year or so in advance of other users.  As far as I
know, it is not possible to a source code license for DGauss.

Our experience with DMol on fairly large clusters (three dozen atoms or so
with two transition metals) has been mixed, with troubles arising in obtaining
self-consistency.  But we have never run a side-by-side test to see whether
the problems are intrisince to these molecules or reflect somehow on the code.
DMol uses partially numerical basis sets.

It is difficult to compare the three codes because of the difference in
philosophy, accuracy requirements, and basis sets.

...dave case

=====================================================================
David A. Case                      |  internet: [email-masked]
Dept. of Molecular Biology, MB1    |  bitnet: case%scripps.edu@sdsc
The Scripps Research Institute     |  fax:   619-554-6717
10666 N. Torrey Pines Rd.          |  phone: 619-554-9768
La Jolla CA 92037  USA             |
=====================================================================

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From: "Donald M. Frederick" <[email-masked]>
Date: Wed, 03 Nov 93 08:36:00 -0800

[ Stuff deleted ]
> CANBERRA  ACT 2601 Australia         |

Probably many readers of this list have already received the mailing from
Gaussian, Inc. announcing the availability for a number of machines of
Gaussian 92 with DFT, Gaussian 92/DFT. I am neither a user nor a chemist,
but looking at the brochure, it seems to be a decent package, with a modest
range of computational options, such as LDA, and various non-local
corrections to LDA, available at a moderate price to educational
institutions. More info can be had from "[email-masked]".

------------------------------------------------------------------------
        Donald Frederick       |      Office of Academic Computing
        [email-masked]       |      University of California, Irvine
             [email-masked]       |      Irvine, CA  92717
        (714) 725-3200         |      FAX (714) 725-2069
-----------------------------------------------------------------------

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From: [email-masked] (alain st-amant)
Date: Wed, 3 Nov 1993 11:52:33 -0500

> with such completely integrated graphics as DMol), particularly suited for

As I had announced early last summer, we should begin freely distributing a DFT
code that I worked on in Montreal and San Francisco.  I've been swamped lately
with teaching, so I haven't been able to put in the final touches, but that
should be completed and the program made ready for distribution during the
Christmas break.  The code is very much similar to DGauss (i.e., it uses
gaussian basis sets).  Only real drawback is that model core potentials will
not be supported in the first release.  Also, the performance may not be as
great as those of the commercial codes.

I will notify this list once the program, DeFT, is ready for distribution by
either anonymous ftp or by tape (at a nominal charge to cover expenses).

Alain St-Amant
[email-masked]

P.S. of course, it would seem that the latest version of Gaussian has DFT
     already incorporated and is now available.