利用半经典微扰理论研究H－H_2O的非弹性碰撞—H_2O的转动、振动激发

利用半经典微扰理论计算了在Ｈ－Ｈ２Ｏ的非弹性碰撞中的Ｈ２Ｏ分子的转动、振动激发，并将计算结果与实验结果进行比较。计算中采用了Ｓｃｈａｔｚ和Ｅｌｇｅｒｓｍａ的半经验势能面，水分子的势函数，包括了谐振和非谐振力函数，在考虑了振动和转动耦合的情况下，通过半经典微扰理论来确定水分子末态的振动量子数。在Ｌｏｖｅｊｏｙ等人最近进行的实验中，当热氢原子入射时，水分子的转动和振动被激发了，而且发现水分子的转动角动量有垂直于水分子平面优先激发的趋势。我们的计算也得到出了相同的结果。

SEMICLASSICAL PERTURBATION THEORY CALCULA TIONS ON THE INELASTIC COLLSIONS OF H AND H 2O ROTATIONAL AND VIBRATIONAL EXCITATIONS OF H 2O

Using a quasiclassical trajectory method, the results including vibration rotation coupled excitations and a aligned propensity of the rotational excitations for H-H 2O colliding system were presented, which are agreement essentially with the recent experiments. In the calculations we have used a semiempirical potential surface due to Schatz and Elgersma. Moreover, for the H 2O molecule, we have considered all harmonic and anharmonic force, according to the Secmiclassical perturbation theory, its final states were numerically determined by looking for the good action variables associated with vibrational motions. The analyses of collision excitation emphasize comparisons with recent expeiments by Lovejey etc. in which fast hydrogen atoms produce vibrationally and rotationally excited water. As their report on the experiments, we also found a propensity for rotational excitation, that is the rotational angular momentum vector is predominantly aligned perpendicular to the water molecule plane.