Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
J Chem Phys. 2012 Sep 21;137(11):114305. doi: 10.1063/1.4752740.
The coefficients at the lowest-order electrostatic, induction, and dispersion terms of the anisotropic long-range potential between the two KRb((1)Σ(+)) molecules are evaluated through the static and dynamic molecular properties using the ab initio coupled cluster techniques. Adiabatic channel potentials for the ground-state molecules are obtained and used for the numerical quantum capture probability calculations in the spirit of the statistical adiabatic channel models. Capture rate coefficients for indistinguishable (polarized) and distinguishable (unpolarized) molecules at temperatures below 10 μK agree well with those computed with the simple isotropic dispersion R(-6) potential, but underestimate the measured ones [Ospelkaus et al., Science 327, 853 (2010)] up to a factor of 3. Preliminary assessment of the effects of higher-order long-range terms, retardation of dispersion forces, and magnetic dipole-dipole interaction does not offer any clear perspectives for drastic improvement of the capture approximation for the reactions studied.
通过使用从头算耦合簇技术，评估了两个 KRb((1)Σ(+)) 分子之间各向异性长程势能的最低阶静电、感应和色散项的系数。得到了基态分子的绝热通道势能，并根据统计绝热通道模型的精神，用于数值量子俘获概率计算。在低于 10 μK 的温度下，对不可分辨（极化）和可分辨（非极化）分子的俘获率系数与用简单各向同性色散 R(-6) 势能计算的结果非常吻合，但与测量值相比，低估了[Ospelkaus 等人，科学 327, 853（2010）]，低估了 3 倍。对更高阶长程项、色散力的延迟和磁偶极-偶极相互作用的初步评估，对于研究反应的俘获近似的大幅改进没有提供任何明确的前景。
