摘要
本文在几个由Persky等人最近得到的扩展-LEPS势上,用变分过渡态理论研究了Cl+H(D)Br、Br+H(D)I的动力学,计算了这些反应的速度常数、势能面瓶颈区性质和动力学同位素效应。我们对Cl+HBr和Cl+DBr反应的计算结果与Persky等在同样势能面上的QCT计算结果及现有的实验结果非常一致;因此,我们认为有关Cl+H(D)Br体系的这个新势能面可用于进一步的动力学计算。但本文对Br+H(D)I的VTST计算与实验和QCT计算差别较大,我们认为歧异的原因是有关Br+H(D)I体系的这个势能面不很理想,有可能它在鞍点附近未能重现真实势能面的性质,因此还需对其进一步鉴定和改进。
Variational transition state theory is used to study the dynamics of Cl+HBr, Cl+DBr, Br+HI and Br+DI reactions on several extended-LEPS surfaces, which were obtained by Persky et al recently. Rate constants, kinetic features on the bottleneck of the PES and kinetic isotopic effects are calculated for the title reactions. Our results for Cl+HBr and Cl+DBr are in good agreement with those of QCT calculations performed by Persky et al on the same surface, and available experiments, thus this surface is recommended to be used in further dynamical calculations. However, our results for Br+HI and Br+DI can't match the QCT calculations and experiments. We think that the divergency between them comes from the possibility that the PES for Br+HI may not reproduce the realistic one exactly in the vicinity of the saddle point and some additional work about this surface is required.
基金
国家自然科学基金
