Subject: Pseudohalogen Deficiencies

From: "Ryan D. Fenno" <rfenno..at..indiana.edu>
Date: Sat, 7 Feb 2004 19:40:47 -0500

Fellow CCLers,

What, if any, are the systematic deficiencies of using pseudohalogens as
cappping atoms for QM/MM calculations, e.g. for pseudobond (J. Chem. Phys. v.110
p.6 (1999)) calculations? For example, a "pseudocarbon" could be a fluorine with
the same basis set as a normal carbon, but have its core electrons replaced with
a pseudopotential that is parametrized to reflect "carbon behavior". 

Hyperchem has this option for its quantum/classical boundaries, so this idea has
been in use for some time. I am also interested in hearing the opinions of those
who have used this option.

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Ryan D. Fenno
Raghavachari Group
Indiana University
Email: rfenno..at..indiana.edu
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