The Langevin capture model is often used to describe barrierless reactive collisions. At very low temperatures, quantum effects may alter this simple capture image and dramatically affect the reaction probability. In this paper, we use the trajectory-ensemble reformulation of quantum mechanics, as recently proposed by one of the authors (Poirier) to compute adiabatic-channel capture probabilities and cross-sections for the highly exothermic reaction Li + CaH($v$ = 0, j = 0) → LiH + Ca, at low and ultra-low temperatures. Each captured quantum trajectory takes full account of tunneling and quantum reflection along the radial collision coordinate. Our approach is found to be very fast and accurate, down to extremely low temperatures. Moreover, it provides an intuitive and practical procedure for determining the capture distance (i.e., where the capture probability is evaluated), which would otherwise be arbitrary.

中文翻译：

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交流：绝热量子轨迹捕获，用于冷和超冷化学反应

Langevin捕获模型通常用于描述无障碍反应碰撞。在非常低的温度下，量子效应可能会改变此简单的捕获图像并极大地影响反应概率。在本文中，我们使用量子力学的轨迹系重新公式化（如作者之一（Poirier）所提出的那样）来计算高放热反应Li + CaH（$v$= 0，j = 0）→LiH + Ca，在低温和超低温下。每个捕获的量子轨迹都充分考虑了沿径向碰撞坐标的隧穿和量子反射。发现我们的方法非常快速且准确，甚至可以降低到极低的温度。此外，它提供了用于确定捕获距离（即在其中评估捕获概率的位置）的直观且实用的过程，否则该捕获距离将是任意的。