Eur. Phys. J. D 31, 27-37 (2004)
https://doi.org/10.1140/epjd/e2004-00111-6

Revisiting the quantum group symmetry of diatomic molecules

¹ School of Informatics Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK
² Institute of Nuclear Research and Nuclear Energy (Permanent address, and after 30 April 2004.) , Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria
³ Instituto de Ciencias Nucleares and Centro de Ciencias Físicas, Universidad National Autónoma de México, Apartado Postal 70-543, Mexico, D.F., 04510 Mexico

Corresponding author: ^a maia.angelova@unn.ac.uk

Received: 12 December 2003
Revised: 16 July 2004
Published online: 24 August 2004

Abstract

We propose a q-deformed model of anharmonic vibrations in diatomic molecules. We study the applicability of the model to the phenomenological Dunham expansion by comparison with experimental data. In contrast with other applications where it is difficult to find a physical interpretation for the deformation parameter, q, in our analysis it is directly related to the third-order coefficient in the Dunham expansion. We study the consistency of the parameters that determine the q-deformed system by comparing them with the vibrational terms fitted to 161 electronic states of diatomic molecules. We show how to include both positive and negative anharmonicities in a simple and systematic way.