Subject: Re: CCL:3-21G(*) BASIS

From: [email-masked] (Per-Ola Norrby)
Date: Thu, 13 Jul 1995 19:05:07 +0200

>Re the recent query about the 3-21G(*) basis set:

        I just want to add my 5 cents worth about a very common source of
confusion:  The original question specified 3-21G*, but it was clear from
the discussion that 3-21G(*) was implied.  Note that 3-21G(*) only adds
d-orbitals to atoms that are believed to "need" them for regular bonds in
easily observed compounds, that is, elements heavier than Ne.  In most
programs it's also possible to specify the less economical set 3-21G*,
which uses polarization on all non-hydrogen atoms.

        Per-Ola Norrby

 *  Per-Ola Norrby
 *  The Royal Danish School of Pharmacy, Dept. of Med. Chem.
 *  Universitetsparken 2, DK 2100 Copenhagen, Denmark
 *  tel. +45-35376777-506, +45-35370850    fax +45-35372209
 *  Internet: [email-masked], [email-masked]