发表机构
Belgian Institute for Space Aeronomy (BIRA-IASB); Department of Chemistry, KU Leuven（比利时空间气旋研究所; 荷语鲁汶大学化学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
Smite是一个Python准经典轨迹工具包，用于双分子碰撞和单分子动力学模拟，支持多种初始条件制备、多种势能面及表面跳跃等高级功能。
AI 中文摘要
我们介绍了Smite，一个用于反应性和非弹性双分子碰撞、单分子动力学以及有限表面模型分子碰撞的准经典轨迹（QCT）模拟的Python工具包。其核心特征是对反应物制备的显式控制：简谐正则模式允许固定量子数、指定能量、热量子布居或基态Wigner采样；转动以固定角动量大小或适用于双原子和多原子转子的热分布来制备。旋转-Morse采样提供了双原子振动和转动的耦合非谐处理，而保存的分子动力学相点则提供了初始条件的替代来源。相同的核传播子可配合实时电子结构计算或用户提供的解析及机器学习势能面运行。其他模块提供约束刚性片段动力学、基于恒温器的制备、具有能量和反冲约束的光电离初始条件，以及在多个势能面上使用近似曲率导出耦合的少开关面跳跃（FSSH）。几何优化、过渡态搜索、交叉点优化、内禀反应坐标跟踪和热化学使用相同的能量和导数接口。分析工具将轨迹与产物能量分配、立体动力学相关性、时间分辨振动特征和独立原子X射线散射联系起来。
英文摘要
We present Smite, a Python toolkit for quasiclassical trajectory (QCT) simulations of reactive and inelastic bimolecular collisions, unimolecular dynamics, and molecular collisions with finite surface models. A central feature is the explicit control of reactant preparation: harmonic normal modes admit fixed quantum numbers, prescribed energies, thermal quantum populations, or ground-state Wigner sampling; rotation is prepared at fixed angular-momentum magnitude or from thermal distributions appropriate to diatomic and polyatomic rotors. Rotating-Morse sampling provides a coupled anharmonic treatment of diatomic vibration and rotation, while saved molecular-dynamics phase points provide an alternative source of initial conditions. The same nuclear propagators operate with on-the-fly electronic-structure calculations or user-supplied analytical and machine-learned potential energy surfaces. Additional modules provide constrained rigid-fragment dynamics, thermostat-based preparation, photoionization initial conditions with energy and recoil constraints, and fewest-switches surface hopping (FSSH) on multiple PESs with approximate curvature-derived couplings. Geometry optimization, transition-state searches, crossing-point optimization, intrinsic-reaction-coordinate following, and thermochemistry use the same energy and derivative interfaces. Analysis tools connect trajectories to product energy partitioning, stereodynamical correlations, time-resolved vibrational signatures, and independent-atom x-ray scattering.
