溶剂惯性通过重定位相空间反应性边界改变产物概率
Solvent Inertia Changes Product Probability by Relocating the Phase-Space Reactivity Boundary
- Hetao Institute of Mathematics and Interdisciplinary Sciences, Shenzhen, China（深圳河套数学与交叉科学研究所）
- School of Mathematics, University of Bristol, University Walk, Bristol, BS8 1TW, United Kingdom（布里斯托大学数学学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过相空间几何而非势能面变化，揭示溶剂惯性改变产物概率的机制，并用线性响应理论预测了噪声下的概率转变区间。
AI中文摘要：
改变溶剂惯性会改变分子哈密顿量的动力学部分，从而改变其在相空间中的流，而无需改变势能面（PES）。我们研究了这如何影响具有两个自由度的溶质-溶剂模型中的产物概率。对于每种溶剂质量，初始条件选择在相同的总能量下。对于这一族初始条件，确定性结果在阈值质量处从到达产物转变为返回反应物。该质量下的初始条件属于过渡态周期轨道的稳定流形。对溶剂动量的弱高斯强迫将结果的突变替换为产物概率的连续变化，该变化发生在与噪声强度的平方根成正比的质量区间上。确定性阈值和线性响应计算预测了该概率变化的位置和宽度，而无需拟合随机模拟。在三种噪声强度下的蒙特卡洛结果与预测在采样不确定性范围内一致。该计算通过完整哈密顿量流的几何结构将溶剂惯性与产物概率联系起来，而非通过改变势能面。
英文摘要：
Changing solvent inertia changes the kinetic part of a molecular Hamiltonian and hence its flow in phase space, without requiring a change in the potential energy surface (PES). We study how this affects product probability in a solute-solvent model with two degrees of freedom. Initial conditions are chosen at the same total energy for each solvent mass. For this family, the deterministic outcome changes from reaching products to returning to reactants at a threshold mass. The initial condition at that mass belongs to the stable manifold of the transition-state periodic orbit. Weak Gaussian forcing of the solvent momentum replaces the abrupt change in outcome by a continuous change in product probability over a mass interval proportional to the square root of the noise strength. The deterministic threshold and a linear response calculation predict the position and width of this probability change without fitting the stochastic simulations. Monte Carlo results at three noise strengths agree with the prediction within sampling uncertainty. The calculation connects solvent inertia to product probability through the geometry of the full Hamiltonian flow, rather than through a change in the PES.
