Hefei National Laboratory for Physical Science at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
J Chem Phys. 2019 Jan 14;150(2):024704. doi: 10.1063/1.5078541.
Surface motion has proven to influence the gas-surface reactions in various ways. An adequate model to describe the complex lattice effects in a relatively simple way is therefore highly desirable. In this work, we have modified the widely used Generalized Langevin Oscillator (GLO) model to incorporate the molecule-surface coupling that plays an important role in activated dissociation of polyatomic molecules on metal surfaces. To this end, taking the well-studied CHD+Ni(111) system as an example, we add a coupling potential linearly dependent on the surface oscillating coordinate, which becomes essential in predicting the dissociative sticking coefficients for reactive scattering. We further scale the mass of the surface oscillator on the basis of a mechanic coupling parameter, which has significantly improved the description of the molecule-surface energy transfer for nonreactive scattering. This so-called modified GLO (MGLO) model retains the simplicity and advantages of the original GLO, while yields much more accurate dynamics results that are in remarkably good agreement with the benchmark data calculated using molecular dynamics. We argue that the MGLO model is applicable to these highly activated gas-surface reactions with strong molecule-surface couplings.
表面运动已被证明以各种方式影响气-固反应。因此，非常需要一个合适的模型来以相对简单的方式描述复杂的晶格效应。在这项工作中，我们修改了广泛使用的广义朗之万振荡器 (GLO) 模型，以纳入在金属表面上多原子分子的活化离解中起重要作用的分子-表面耦合。为此，以研究充分的 CHD+Ni(111) 体系为例，我们添加了一个与表面振动坐标线性相关的耦合势，这对于预测反应性散射的离解 sticking 系数至关重要。我们进一步根据力学耦合参数对表面振荡器的质量进行缩放，这极大地改善了非反应性散射的分子-表面能量传递的描述。这种所谓的修正 GLO (MGLO) 模型保留了原始 GLO 的简单性和优势，同时产生了更准确的动力学结果，与使用分子动力学计算的基准数据非常吻合。我们认为，MGLO 模型适用于具有强分子-表面耦合的这些高度活化的气-固反应。
