Phase transition from u ( 3 ) to o ( 4 ) in the model is also analyzed in detail . finally , the vibron model is used to describe diatomic molecules . fitting to vibrational energy spectra is performed using both transitional theory and dynamical symmetry limit theory within the same framework 利用建立在該嚴格解基礎上的計算程序討論了u ( 4 )振動子模型的過渡區(qū)理論對雙原子分子振動能譜的描述,并與o ( 4 )極限的計算結果做了比較。