Theoretical investigations of molecular collisions and chemical reactions at ultracold temperatures

近年来，冷却和捕获各种原子和分子样品的技术的发展为探测和操纵低温和超低温下的化学反应创造了令人兴奋的机会。对低温和超低温下原子和分子相互作用的理论研究已经成为这一努力的组成部分。为了进一步推动这一领域的进展，将以H2-H2和H2-HD系统为例，对冷分子和超冷分子碰撞(包括异核分子)中的转动和振动跃迁进行定量计算。此外，还将对低温和超冷温度下具有重要天体物理意义的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-分子和原子-分子碰撞。还没有为这种类型的计算开发通用计算机代码。分子-分子散射计算将使用在上一个资金周期与不列颠哥伦比亚大学罗曼·克雷姆斯联合开发的量子散射程序进行。一旦完全实施并针对硅藻-硅藻碰撞的一般情况进行测试，该代码将向更广泛的科学界提供。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。开发的计算算法将同样适用于相关领域的分子现象，例如大气物理和天体物理。将为一名本科生提供暑期支持，为一名博士后学者提供部分支持，以开展AMO物理学前沿领域的研究。预计博士后学者将在工作完成后担任终身教职或类似职位，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.