Theoretical investigations of molecular collisions and chemical reactions at ultracold temperatures

近年来，各种原子和分子样品的冷却和捕获技术的发展为在低温和超低温下探测和操纵化学反应创造了令人兴奋的机会。原子和分子在低温和超低温下相互作用的理论研究已经成为这一努力的一个组成部分。为了进一步推进这一领域的研究进展，我们将以H2-H2和H2-HD体系为例，对包括异核分子在内的冷分子和超冷分子碰撞中的旋转和振动跃迁进行定量计算。此外，量子力学计算将在低温和超低温下对天体物理学重要的O+OH反应进行。最先进的量子散射方法将用于研究分子-分子和原子-分子碰撞。一般用途的计算机代码还没有为这类计算开发出来。分子-分子散射计算将使用与Roman Krems（不列颠哥伦比亚大学）在上一个资助周期共同开发的量子散射代码进行。一旦该代码在硅藻-硅藻碰撞的一般情况下得到充分实施和测试，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。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。暑期资助本科生1名，部分资助博士后1名，在AMO物理前沿领域开展研究。博士后学者在完成工作后将有望获得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.