U(2) algebraic model applied to stretching vibrational spectra of   tetrahedral molecules
  The highly excited stretching vibrational energy levels and the intensities of infrared transitions in tetrahedral molecules are studied in a U(2) algebraic model. Its applications to silane and silicon tetrafluoride are presented with smaller standard deviations than those of other models. 
Xi-Wen Hou and Zhong-Qi Ma