Litman Y, Pós E S, Box C L, Martinazzo R, Maurer R J, Rossi M
MPI for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany.
Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom.
J Chem Phys. 2022 May 21;156(19):194106. doi: 10.1063/5.0088399.
Reactions involving adsorbates on metallic surfaces and impurities in bulk metals are ubiquitous in a wide range of technological applications. The theoretical modeling of such reactions presents a formidable challenge for theory because nuclear quantum effects (NQEs) can play a prominent role and the coupling of the atomic motion with the electrons in the metal gives rise to important non-adiabatic effects (NAEs) that alter atomic dynamics. In this work, we derive a theoretical framework that captures both NQEs and NAEs and, due to its high efficiency, can be applied to first-principles calculations of reaction rates in high-dimensional realistic systems. More specifically, we develop a method that we coin ring polymer instanton with explicit friction (RPI-EF), starting from the ring polymer instanton formalism applied to a system-bath model. We derive general equations that incorporate the spatial and frequency dependence of the friction tensor and then combine this method with the ab initio electronic friction formalism for the calculation of thermal reaction rates. We show that the connection between RPI-EF and the form of the electronic friction tensor presented in this work does not require any further approximations, and it is expected to be valid as long as the approximations of both underlying theories remain valid.
涉及金属表面吸附物和块状金属中杂质的反应在广泛的技术应用中无处不在。此类反应的理论建模对理论而言是一项艰巨的挑战，因为核量子效应（NQEs）可能起显著作用，且原子运动与金属中的电子耦合会产生改变原子动力学的重要非绝热效应（NAEs）。在这项工作中，我们推导了一个既包含NQEs又包含NAEs的理论框架，并且由于其高效性，可应用于高维实际系统中反应速率的第一性原理计算。更具体地说，我们从应用于系统 - 浴模型的环聚合物瞬子形式出发，开发了一种我们称之为带显式摩擦的环聚合物瞬子（RPI - EF）的方法。我们推导了包含摩擦张量的空间和频率依赖性的一般方程，然后将此方法与用于计算热反应速率的从头算电子摩擦形式相结合。我们表明，RPI - EF与本文中提出的电子摩擦张量形式之间的联系不需要任何进一步的近似，并且只要两个基础理论的近似仍然有效，预计它就是有效的。
