Subject: more on AIM analysis when G98W fails

From: "Shobe, Dave" <[email-masked]>
Date: Tue, 12 Sep 2000 11:25:41 -0400

A few more questions about options when G98W fails:

#1.  The AIMPAC download webpage
http://www.chemistry.mcmaster.ca/aimpac/
describes the programs as being "vectorized".
Will these run on my computer, which is not only a single-processor machine,
but
is Windows rather than Unix or Linux?

#2.  Is it possible to get bond orders, or has Cioslowski et al only made
these available thru Gaussian?

#3.  It certainly would be easier to do this thru Gaussian.
WHY does AIM=(charges,BO) fail so often?  I couldn't even
get pyrrole (HF/6-311++G**//CBS-4) to work.  Has anyone
had luck with changing to a different basis set, or anything
like that??

--David Shobe
Süd-Chemie Inc.
phone (502) 634-7409
fax     (502) 634-7724
email  [email-masked]

Any opinions herein are not necessarily representative of Süd-Chemie.

---

From: "C.F. Matta" <[email-masked]>
Date: Tue, 12 Sep 2000 16:13:14 -0400 (EDT)

Hi again,

Please read my answers amongst your lines below:

> but is Windows rather than Unix or Linux?

Nope, AIPAC are designed for a UNIX or a LINUX platform. Nothing would
prevent one to compile them using a FORTRAN77 compiler running under
Windows, but one may have to do a few modifications.  There is a Windows
program that implements the Quantum Theory of Atoms-In-Molecules (AIM) ,
it is called AIM2000, and also available free of charge from:

         http://gauss.fh-bielefeld.de/aim2000/

> these available thru Gaussian?

I wrote a shell scripts that calculates the delocalization/localization 
indeces using the integration files that AIMPAC produces.
 
> had luck with changing to a different basis set, or anything

The GAUSSIAN implementation of AIM does indeed fails frequently. On the
other hand, the AIMPAC software very rarely fails (Never happened to in
five years since I started using it). 

AIMPAC is very reliable, but requires more user input (and thus more
flexibility and more output) than the AIM-options in GUAUSSIAN.

Hope the above helps.

 Cherif F. Matta

___________________________________________________________________________

  Cherif F. Matta                         tel. (905) 525-9140 ext. 22502
  Chemistry Department                    fax  (905) 522-2509
  McMaster University
  Hamilton, Ontario, CANADA L8S 4M1.                ______________________
                                                    | "Choice not chance
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 Member of the Board of Governors of the University |  destiny". Anonymous
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