Subject: Re:6-31G set for iodine

From: "Vitaly A. Rassolov" <[email-masked]>
Date: Mon, 8 Dec 1997 11:43:39 -0600

Dear CCLers:

I want to alert those who are interested in all-electron basis sets for
heavier elements that some basis sets beyond the second row are mislabeled.
For instance, the 6-31G notation for the basis set has a very definite
meaning:  This set has 6 basis functions for each core orbital, and the
valence orbitals are split into two contractions with 3 and 1 Gaussians in
each.  Traditionally, these sets also share s and p exponents, and are
either fully or nearly fully optimized.  Unfortunately, very different
basis sets are often labeled as 6-31G or 6-311G, with stars or (d) attached
to them.  Gaussian 94 even mislabels Wachters-Hay set for first-row
transition metals as 6-311G in its library (granted, they explain it in the
manual, but some people don't read those things).  The use of mislabeled
(but often otherwise fine) basis sets can lead to the imbalance between the
ligands and metals.

Currently, the "true" 6-31G(stars or d's) and 6-311G(stars or d's) are not
available beyond Ar.  We extended 6-31G* through Zn, and in the process of
publishing them.  Ahlrichs' group also has some fully optimized sets
through Kr.  Those who need basis sets can check

http://www.emsl.pnl.gov:2080/forms/basisform.html

for the available basis sets and their descriptions.

	Vitaly Rassolov
	Department of Chemistry		tel. (847) 491-3423
	Northwestern University
	2145 Sheridan Rd.		[email-masked]
	Evanston, IL 60208-3113