For H_2O such local mode phenomena is due to the strong unharmonic of potential energy.For H_2O_2, besides unharmonic, it is further due to a complicate coupling between these two OH vibration mode.
2O分子这种现象是由于强非谐性造成,而H_2O_2分子除上述原因外,还与两个OH键振模间复杂耦合有关.