Subject: Linear dependency/G98 (followup)

From: "Feller, David F" <[email-masked]>
Date: Fri, 21 Jan 2000 09:15:40 -0800

I just noticed Jens Antony's mail on this same topic and read
Doug Fox's reply.  I think Doug is correct in stating that most
linear dependency arises from the presence of diffuse functions
in basis sets, but it would be an oversimplication to imply that
this is the only case where it arises or that the consequences
of eliminating vectors is small.

The case that brought this issue to our attention was a calculation
on the argon atom.  If you use the (s,p) functions taken from the
correlation consistent cc-pV5Z set, you will obtain the following
SCF energies:
Ar Atom E(SCF)
-526.817342 (G94, MOLPRO, MELDF, etc.)
-526.813116 (G98)

As you can see, the difference in this case is more than 4 millihartrees
for a single atom.

Dave

David Feller                                | [email-masked] 
Environmental Molecular Sciences Lab., K8-91| Box 999
Pacific Northwest National Laboratory       | Richland, WA 99352 
                                            | Fax: 509-375-6631