Department of Chemistry and Biochemistry, Texas Tech University , Lubbock, Texas 79409-1061, United States.
Department of Chemistry and Biochemistry, Siena College , Loudonville, New York 12211, United States.
J Am Chem Soc. 2017 Mar 15;139(10):3570-3590. doi: 10.1021/jacs.6b12017. Epub 2017 Feb 9.
In a direct dynamics simulation, the technologies of chemical dynamics and electronic structure theory are coupled so that the potential energy, gradient, and Hessian required from the simulation are obtained directly from the electronic structure theory. These simulations are extensively used to (1) interpret experimental results and understand the atomic-level dynamics of chemical reactions; (2) illustrate the ability of classical simulations to correctly interpret and predict chemical dynamics when quantum effects are expected to be unimportant; (3) obtain the correct classical dynamics predicted by an electronic structure theory; (4) determine a deeper understanding of when statistical theories are valid for predicting the mechanisms and rates of chemical reactions; and (5) discover new reaction pathways and chemical dynamics. Direct dynamics simulation studies are described for bimolecular S2 nucleophilic substitution, unimolecular decomposition, post-transition-state dynamics, mass spectrometry experiments, and semiclassical vibrational spectra. Also included are discussions of quantum effects, the accuracy of classical chemical dynamics simulation, and the methodology of direct dynamics.
在直接动力学模拟中，化学动力学和电子结构理论的技术是耦合的，因此模拟所需的势能、梯度和 Hessian 可以直接从电子结构理论中获得。这些模拟被广泛用于：（1）解释实验结果并理解化学反应的原子水平动力学；（2）说明经典模拟在量子效应不重要时正确解释和预测化学动力学的能力；（3）获得电子结构理论预测的正确经典动力学；（4）确定统计理论何时适用于预测化学反应的机制和速率；（5）发现新的反应途径和化学动力学。本文描述了双分子 S2 亲核取代、单分子分解、过渡后态动力学、质谱实验和半经典振动光谱的直接动力学模拟研究。还讨论了量子效应、经典化学动力学模拟的准确性以及直接动力学的方法学。
