Hou, XW (reprint author), Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
The dynamical comparison of entanglement, mensured by linear entropy and negativity, is carried out for initial pure separable states in vibrations of H2O and SO2. It is shown that both measures of all initial state with local-mode character have the same period for H2O, while those of all initial state with normal-mode character are no longer identical in period. When the total quantum number of the initial state is one, both measures rise and lower together with the period for HO2 being larger than that for SO2. For a suitable state in HO2, both measures exhibit a beat phenomenon with a long period.