Subject: Re: CCL:CALCS ON HCN/HNC ISOMERIZATION

From: Robert_Topper <[email-masked]>
Date: Mon, 8 Aug 1994 10:19:21 -0400

With respect to the HCN/HNC isomerization; I can recommend
a few useful references as a starting point:

J.M. Bowman, B. Gazdy, J.A. Bentley, T.J. Lee, and C.E. Dateo,
J. Chem. Phys. 99, 308 (1993); T.J. Lee, C.E. Dateo, B. Gazdy, and
J.M. Bowman, J. Phys. Chem. 97, 8937 (1993); J.N. Murrell, S. Carter,
and L.O. Halonen, J. Mol. Spec. 93, 307 (1982).

In the first of these papers, experimental values are given for
the bond lengths and fundamental frequencies for HCN and HNC,
taken from several papers by Klemperer/Lehman et. al. .
For HCN, the fundamentals are 3311, 713, and 2097 cm^-1; 
for HNC, "    "           "   3653, 477, and 2029 cm^-1. 

The papers by Bowman et.al. and Murrell et.al. seem to be to indicate
that when high-level electronic structure methods are used to determine
the potential surface and (anharmonic) vibrational perturbation theory
[or DVR-DGB variational calculations] are used to calculate the vibrational
energy levels, the transition frequencies reproduce experimental
values within about 20 cm^-1 or less for both isomers.

I hope that this is useful information.
best, rqt

************************************************************************
 Prof. Robert Q. Topper               internet:   [email-masked]
 Department of Chemistry              phone:      (212) 353-4378
 The Cooper Union                     FAX:        (212) 353-4341 
 Cooper Square                        subway:     take the N/R to 8th/NYU 
 New York, NY 10003 USA                           or the 6 to Astor Place
************************************************************************
Thermodynamics forever...