Subject: ? re partial atomic charges

From: "Hr Dr. S. Shapiro" <[email-masked]>
Date: Mon, 8 Jan 1996 14:02:53 +0100 (MET)

Dear Colleagues;

     For some calculations that I wish to perform, I need to have partial
atomic charges; these I can generate without problems using MOPAC.  However,
some of the molecules in which I am interested have a lone electron pair
on an unionised phenolic group, and the software which I am using requires
that I enter a partial atomic charge for this lone pair.  Since my MOPAC
(AM1) calculations only generated partial atomic charges for the hydrogen
and heavy (carbon, oxygen) atoms, is there a single "standard" value for the
partial atomic charge on this lone pair that I should use, or will the par-
tial atomic charge on the lone pair vary substantially with the pattern of
substitution around the phenol ring?  Or should it simply be set equal to
zero?

     I thank all responders in advance for kindly sharing their information
and thoughts on this matter with me.

Respectfully,

(Dr.) S. Shapiro
Inst. f. orale Mikrobiol. u. allg. Immunol.
Zent. f. Zahn-, Mund- u. Kieferheilkd. der Univ. ZH
Plattenstr. 11
Postfach
CH-8028 ZH 7

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