原子-振子散射振转激发跃迁几率的理论计算

在相互作用表象中,利用角动量耦合理论,导出了原子-振子散射的含时量子计算公式,并计算了He-H₂体系的振转激发态-态跃迁几率和分散射截面。结果表明:(1)相互作用表象波函数在坐标空间中具有较高的定域性,随时间演化几乎不变形,因此在计算散射量时具有很高的精度,与标准的密耦合(CC)法的计算结果符合很好;(2)增加的振动部分对计算时间的影响取决于对一势能矩阵的积分,而在该积分中仅含基态的计算就能给出较为理想的散射截面,与CC法相比节省近一倍的计算时间。 关键词：

THEORETICAL CALCULATION OF VIBRATIONAL AND ROTATIONAL TRANSITION PROBABILITIES FOR THE ATOM-OSCILLATOR SCATTERING

In the interaction representation, the time-dependent quantum calculation formulas for the atom-oscillator scattering are derived by using angular momentum coupling theory, and the vibrational and rotational transition probabilities and the partial cross sections for the He-H₂ system are calculated. The results show that: (1) the interaction picture wave function is highly localized in coordinate space and varies slowly in time, therefore, we are able to obtain higher accuracy in calculating scattering quantities, and the calculated results are in excellent agreement with that of CC method; (2) the effect of the vibration term on the calculating time is dependent upon the integration of the potential matrix, in which a calculation including only the ground state gives remarkably good results.