Wong Kin-Yiu, Gao Jiali
Department of Chemistry and Minnesota Supercomputing Institute, University of Minnesota, Smith Hall, Minneapolis, Minnesota 55455, USA.
J Chem Phys. 2007 Dec 7;127(21):211103. doi: 10.1063/1.2812648.
Based on Kleinert's variational perturbation (KP) theory [Path Integrals in Quantum Mechanics, Statistics, Polymer Physics, and Financial Markets, 3rd ed. (World Scientific, Singapore, 2004)], we present an analytic path-integral approach for computing the effective centroid potential. The approach enables the KP theory to be applied to any realistic systems beyond the first-order perturbation (i.e., the original Feynman-Kleinert [Phys. Rev. A 34, 5080 (1986)] variational method). Accurate values are obtained for several systems in which exact quantum results are known. Furthermore, the computed kinetic isotope effects for a series of proton transfer reactions, in which the potential energy surfaces are evaluated by density-functional theory, are in good accordance with experiments. We hope that our method could be used by non-path-integral experts or experimentalists as a "black box" for any given system.
基于克莱纳特的变分微扰（KP）理论[《量子力学、统计、高分子物理和金融市场中的路径积分》，第3版（世界科学出版社，新加坡，2004年）]，我们提出了一种用于计算有效质心势的解析路径积分方法。该方法使KP理论能够应用于超出一阶微扰（即原始的费曼 - 克莱纳特[《物理评论A》34，5080（1986）]变分方法）的任何实际系统。对于几个已知精确量子结果的系统，我们获得了精确值。此外，对于一系列质子转移反应，通过密度泛函理论评估其势能面，计算得到的动力学同位素效应与实验结果高度吻合。我们希望我们的方法可以被非路径积分专家或实验人员用作针对任何给定系统的“黑匣子”。
