Subject: G94: How to set parameters for CHELPG?

From: Bjoern Rabenstein <[email-masked]>
Date: Mon, 17 Nov 1997 14:00:19 +0100

Dear CCLers!

I'm currently trying to do some experiments with the CHELPG routine of
Gaussian94 to fit atomic partial charges to the electrostatic potential.
I have problems to change or add parameters:

(i) How additional van-der-Waals radii are set? e.g. radius of Fe is
unknown, but my molecule contains a Fe atom.

(ii) How can I change (if possible?!?) the maximum radius, up to where
grid points are considered for the fit? Has anybody already done this?
And what was the result? (Of course, as already discussed in this list,
the monopole will dominate more and more with increasing radius, thus in
general absolute values of the charges will decrease, if the molecule
has over-all electroneutrality. But are their any special changings of
single charges possible?)

Bye!
-- 
            Bjoern Rabenstein * PhD student * Freie Universitaet Berlin
 Inst. f. Kristallographie * AG Knapp * Takustrasse 6  * D-14195 Berlin
                        [phone] +49-30-838-3484   [fax] +49-30-838-3464
 [email] [email-masked]  [WWW] http://www.chemie.fu-berlin.de/~rabe/