Subject: anharmonic oscillator wavefunctions

From: Steve Williams <[email-masked]>
Date: Thu, 08 Nov 2001 15:01:18 -0500

I have a colleague who is interested in computing Franck-Condon factors, 
for which he needs anharmonic oscillator wavefunctions.  I think that I can 
provide him with some good potentials (he is interested in first row 
diatomics) from something like ccsd(t) scans with one of the aug-cc basis 
sets.  My plan was to fit the resulting potential to a Morse function, then 
get the anharmonic wavefunctions by diagonalizing the anharmonic (Morse) 
Hamiltonian on a basis of harmonic oscillator functions.  I am not certain 
that this fit will be good enough, particularly in the repulsive regime.  I 
have poked about in the literature some, but have not yet found the 
definitive "best" way to do this.

I suspect there are some ccl users who know about getting good quality 
vibrational wavefunctions from ab initio potentials, and there may be some 
existing code out there to help solve this problem.  I'd appreciate any 
suggestions, pointers to papers that I have overlooked, or codes.  I'll 
post a summary on this topic soon.

Steve Williams

Steve Williams
A. R. Smith Department of Chemistry
Appalachian State University
Boone, NC 28608
USA
828-262-2965