Computer Simulation of Chemical Dynamics

有了化学系理论和计算计划的这笔赠款，哈斯教授将使用计算机模拟在微观水平上研究化学动力学。这些模拟的结果将帮助实验者估计重要化学反应的速率。在多原子分子的经典轨迹模拟中，将测试不同的方法来处理零点能量。这将在一定程度上涉及与量子动力学计算的比较。通过研究(1)与特定模式分解有关的波函数和速率常数的性质；(2)解离产物中的能量分配；(3)微正则激发分子的非谐性和振动/转动耦合的处理，将加强单分子反应动力学的理论。我们将研究缔合反应的微观性质，如能量传递途径和角动量的作用，并建立准确的缔合速率常数模型。为了弥合溶液和气相化学动力学之间的差距，将研究溶剂化反应物的缔合。将对SN2亲核取代反应的相空间瓶颈和中心势垒重新跨越进行研究。

With this grant in the Theoretical and Computational Program of the Chemistry Division, professor Hase will use computer simulation to study chemical dynamics at a microscopic level. The results of these simulations will help experimentalists estimate the rates of important chemical reactions. Different methods will be tested for treating zero point energy in classical trajectory simulations of polyatomic molecules. This will involve, in part, comparisons with quantum dynamical calculations. The theory of unimolecular reaction dynamics will be enhanced by investigating (1) the properties of wave functions and rate constants associated with mode specific decomposition; (2) energy partioning in dissociation products; and (3) the treatment of anharmonicity and vibrational/rotational coupling for microcanonically excited molecules. Microscopic properties of association reactions such as energy transfer pathways and the role of angular momentum will be studied, and an accurate model will be developed for the association rate constant. To bridge the gap between solution and gas-phase chemical kinetics, the association of solvated reactants will be studied. A study of phase space bottlenecks and central barrier recrossing will be performed for SN2 nucleophilic substitution reactions.