Subject: CCL:Re:1,5-Diaminotetrazole aminogroup structure

From: "Stefan Fau" <[email-masked]>
Date: Wed, 15 Aug 2001 12:29:53 -0400

Hi Alexander,

Prof. Norrby raised valid points. However, there
also seems to be a problem with respect to the basis
set you used. It appears that molecules with many
(or maybe neighboring) nitrogen atoms are not described
well enough by split valence plus polarization basis sets
like 6-31G(d) or cc-pVDZ. This was illustrated on the
example of N6. Various authors found structures close
to C2h using split valence basis sets. Upon addition of
diffuse functions (aug-cc-pVDZ) or when using cc-pVTZ,
the molecule was calculated to have C2h symmetry.
We believe the interaction of lone pairs to be responsible
for the phenomenon.

See M. Tobita, R.J. Bartlett, J. Phys. Chem. A 2001,
105, 4107 and references cited therein.

Stefan
______________________________________________________________________
Dr. Stefan Fau                    |      [email-masked]
Quantum Theory Project     |     (352) 392-6714
University of Florida
Gainesville, FL 32611-8435