Application of a symmetry-adapted algebraic model to the vibratioinal   spectrum of methane
  The stretching and bending vibrations of methane are studied in the framework of a symmetry-adapted algebraic model. The model is based on the realization of the one-dimensional Morse potential in terms of a $U(2)$ algebra. For the 44 observed energies we obtain a fit with a r.m.s. deviation of 1.16 cm$^{-1}$ which is an order of magnitude more accurate than previous algebraic calculations. 
R. Lemus, F. Perez-Bernal, A. Frank, R. Bijker and J.M. Arias   (ICN/UNAM, Mexico and Sevilla, Spain)