Theoretical investigations of molecular collisions and chemical reactions at ultracold temperatures

近年来，用于冷却和捕获各种原子和分子样品的技术的发展为在冷和超冷温度下探测和操纵化学反应创造了令人兴奋的机会。在低温和超低温下的原子和分子相互作用的理论研究已成为这一奋进的一个组成部分。为了进一步推进这一领域的研究，本文以H_2-H_2和H_2-HD体系为例，对冷态和超冷态分子碰撞中的转动跃迁和振动跃迁进行了定量计算。此外，还将对低温和超低温下天体物理上重要的O+OH反应进行量子力学计算。最先进的量子散射方法将被用来研究分子与分子和原子与分子的碰撞。通用计算机代码尚未开发用于这种类型的计算。分子-分子散射计算将使用与Roman Krems（不列颠哥伦比亚省大学）在上一个资助周期联合开发的量子散射代码进行。一旦该代码得到充分实施并在硅藻-硅藻碰撞的一般情况下进行测试，将向更广泛的科学界提供该代码。这些研究将对原子，分子和光学（AMO）物理，物理化学和天体化学之间的界面研究产生广泛的影响。所开发的计算算法将同样适用于相关领域的分子现象，例如，大气物理学和天体物理学。将为本科生提供暑期支持，并为博士后学者提供部分支持，以开展AMO物理前沿领域的研究。博士后学者将有望在完成工作后担任终身职位或类似职位，并继续指导学生和学者。

The development of techniques for cooling and trapping of a wide variety of atomic and molecular samples in recent years has created exciting opportunities for probing and manipulating chemical reactions at cold and ultracold temperatures. Theoretical studies of atomic and molecular interactions at cold and ultracold temperatures have become an integral part of this endeavor. To further advance progress in this field, quantitative calculations of rotational and vibrational transitions in cold and ultracold molecule collisions, including heteronuclear molecules, will be carried out by taking the H2-H2 and H2-HD systems as illustrative examples. In addition, quantum mechanical calculations will be carried out on the astrophysically important O+OH reaction at cold and ultracold temperatures. State-of-the-art quantum scattering methods will be used to investigate the molecule-molecule and atom-molecule collisions. General purpose computer codes have not been developed for this type of calculations. The molecule-molecule scattering calculations will be performed using a quantum scattering code jointly developed with Roman Krems (University of British Columbia) during the previous funding cycle. The code will be made available to the broader scientific community once it has been fully implemented and tested for the general case of diatom-diatom collisions. The studies will have broad impact on research at the interface between Atomic, Molecular and Optical (AMO) Physics, Physical Chemistry, and Astrochemistry. The computational algorithms developed will be equally applicable for molecular phenomena in related fields, for example, Atmospheric physics and Astrophysics. Summer support for an undergraduate student and partial support for a postdoctoral scholar will be provided to carry out research in the frontier area of AMO Physics. The postdoctoral scholar will be expected to take up a tenure track or similar position after completion of the work and to continue to mentor students and scholars.