Symmetry-adapted algebraic description of stretching and bending   vibrations of ozone
  The vibrational excitations of ozone, including both bending and stretching vibrations, are studied in the framework of a symmetry-adapted algebraic approach. This method is based on the isomorphism between the U(2) algebra and the one-dimensional Morse oscillator, and the introduction of point group symmetry techniques. The use of symmetry-adapted interactions, which in the harmonic limit have a clear physical interpretation, makes it possible to systematically include higher order terms and anharmonicities. A least-square fit to all published experimental levels (up to ten quanta) of 16 O_3 and 18 O_3 yields a r.m.s. deviation of 2.5 and 1.0 1/cm, respectively. 
F. Perez-Bernal, J.M. Arias, A. Frank, R. Lemus and R. Bijker   (Sevilla, Spain and ICN/UNAM, Mexico)