Subject: Re: CCL:dipoles

From: Russ Johnson <russell.johnson{at}nist.gov>
Date: Thu, 09 Sep 2004 13:15:37 -0400

The NIST Computational Chemistry Comparison and Benchmark Database (http://srdata.nist.gov/cccbdb) has a page for comparing experimental and calculated dipoles (section IV.E.1). It has 162 molecules with experimental dipoles. While it doesn't have the 6-31++G** basis set it does have both 6-31G* and  6-31+G**. For BLYP, B3LYP, B3PW91, mPW1PW91, and PBEPBE the rms differences improve on going to the larger basis set.

At 16:28 2004/09/09 +0200, you wrote:
>Dear all,
>Is there anyone who knows why dipole moments calcultaed with a 6-31++G** basis set are worser (deviate more from experimental values) than those calculated with a 6-31G* basis set?
>I used B3LYP as calculation method and I tested it for 10 molecules.
>Thank you in advance for help,
>Best regards, Goedele
>
>Drs. Goedele Roos

Dr. Russell D. Johnson III 
Research Chemist 
National Institute of Standards and Technology 
Computational Chemistry Group 
100 Bureau Drive, Stop 8380 
Gaithersburg, MD 20899-8380 
voice 301+975-2513     fax  301+869-4020 
email: russell.johnson{at}nist.gov