Subject: Visualizing orbitals

From: Deepak Singh <[email-masked]>
Date: Tue, 14 Dec 1999 11:40:44 -0500

Here is the text from a post I made a while ago.  Sorry for the delay in
this message but I was trying out a few options.

----------------------------------------
Hi,

I have been looking into software (for IRIX) that will allow me to
visualize MO's, charge densities etc.  I heard a lot about AVS but that
seems to have disappeared.  I ran into IBM's 'Open Visualization Data
Explorer' today and it seems to be similar to AVS.  I would like to know

if people have used this a lot with G98/94, GAMESS and MOPAC?  Is the
performance similar to AVS?

Thanks

Deepak
-------------------------------------------

I got a lot of replies.  Amongst other things, I was told that AVS still
exists as AVS Express.  Here is a post that covers AVS
Express/IBM Explorer

--------------------------------------------------------
Hi Deepak,
    AVS the company still exists (www.avs.com), and AVS the package
(AVS5) has
been reincarnated as Viz Express.    I have used it to visualize charge
densities
and other spatial fields with some success (see my web page for an old
example of
delta-rho at a defect in a grain boundary).   However I found it limited
in other
ways-- volume rendering for example.      AVS is proprietary and costs ~

$1000/copy (I run it on an SGI Indigo-2).    I have been thinking about
trying
Data Explorer-- I know a number of people who have used it for chemistry

applications and have been very happy with it.   Also the price is right

(free).    There is some history about AVS and Data Explorer-- one broke
off from
the other-- they used to be part of the same product-- but I don't
recall the
details.    IBM's Data Explorer used to be proprietary but it recently
went
'open'.
   Regarding performance-- I have no idea, but I suspect that the bottom
line will
be the quality of your workstation's graphics board  (I have an SGI
Indigo2 High
Impact/R10000/195 MHz and AVS runs very well with that).
   I have also just returned from Supercomputing '99 and saw a demo of a
new
visualization package, Amira, which was used to do some fantastic volume
rendering
of scalar fields (for an astrophysics application, but it would seem
very
applicable to visualizing molecular orbitals)-- check out
http://www.amiravis.com
or www.tgs.com.     I am planning to do this myself :-)
   Cheers,
     Susan
-----------------------------------------------------------

After looking at the IBM product and some other suggestions, I decided
that for the price and effort the best out there are still MOLDEN and
MOLEKEL.  The latter which I had never used is excellent for use with
Gaussian and GAMESS.  MOLDEN's vrml pictures are great too.

I still would like to spend more time with IBM explorer as the pictures
are very pretty but at a later date

MOLDEN is available at

http://www.caos.kun.nl/~schaft/molden/molden.html

and MOLEKEL (only for SGI's) at

http://igc.ethz.ch/molekel/

Thanks to everyone who replied

Regards

Deepak.

--
**********************************************************************
Deepak Singh                        Tel : (315)443 1739 (w)
Graduate Student                          (315)472 9659 (h)
Dept. of Chemistry                  Fax : (315)443 4070
Syracuse University               email : [email-masked]
1-014 CST, Syracuse                 URL : http://web.syr.edu/~desingh
NY 13244

"Violence is the last refuge of the incompetent." --- Salvor Hardin
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