He-Na2体系低温下的冷碰撞研究

在已经拟合好的He-Na₂体系势能面上，根据原子-双原子分子的非反应性碰撞动力学的相关基本理论，在空间固定坐标系下，采用严格的密耦方法求解了He原子和Na₂分子的转动非弹性碰撞动力学方程.并对He-Na₂体系的微分散射截面、积分截面作了详细的分析,结果与实验符合得比较好.结果表明：（1）弹性散射（Δj=0）截面远大于非弹性截面；（2）较小Δj的跃迁主要产生前向散射，随着Δj的增加，后向散射的几率增加 关键词： 2体系')" href="#">He-Na₂体系 密耦方法 微分散射截面 积分截面

Low-temperature collisions of Na2 with He

The close coupling calculation of rotationally inelastic collision of He with Na₂ is first performed by employing a recently computed ab initio potential energy surface. The process of rovibrational energy excitation and relaxation of Na₂ in collision with He has been studied in detail based on the single and double exitations coupled cluster with a noniterative perturbation treatment of triple excitations CCSD （T） potential energy surface. Our results are in good agreement with the experimental results. Our results show that: （1）The elastic cross section（Δj=0） is much larger than the inelastic cross section. （2）The largest amplitude occurs at small scattering angles. At low Δj transition, the He projectile is predominantly forward scattering. Backward scattering occurs as Δj increases. （3）For inelastic cross section, the most effective transition is that with Δj=2.（4）The fast narrow diffraction oscillations in the cross sections are the obvious characteristics for the low Δj inelastic transitions, which decreases with increasing j. （5）The elastic differential-cross-sections（DCS）provides a useful visualization of rotational rainbows at low translational energy. It is beneficial to reducing the loss in molecular cooling and trapping.