Nonstatistical dynamics is important for many chemical reactions. The Rice-Ramsperger-Kassel-Marcus (RRKM) theory of unimolecular kinetics assumes a reactant molecule maintains a statistical microcanonical ensemble of vibrational states during its dissociation so that its unimolecular dynamics are time independent. Such dynamics results when the reactant's atomic motion is chaotic or irregular. Intrinsic non-RRKM dynamics occurs when part of the reactant's phase space consists of quasiperiodic/regular motion and a bottleneck exists, so that the unimolecular rate constant is time dependent. Nonrandom excitation of a molecule may result in short-time apparent non-RRKM dynamics. For rotational activation, the 2J + 1 K levels for a particular J may be highly mixed, making K an active degree of freedom, or K may be a good quantum number and an adiabatic degree of freedom. Nonstatistical dynamics is often important for bimolecular reactions and their intermediates and for product-energy partitioning of bimolecular and unimolecular reactions. Post-transition state dynamics is often highly complex and nonstatistical.

中文翻译：

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非统计反应动力学。

非统计动力学对于许多化学反应很重要。Rice-Ramsperger-Kassel-Marcus（RRKM）的单分子动力学理论认为，反应物分子在解离期间会保持统计的振动态微规范集合，因此其单分子动力学与时间无关。当反应物的原子运动混乱或不规则时，就会产生这种动力学。当部分反应物的相空间由准周期性/规则运动组成并且存在瓶颈时，就会发生内在的非RRKM动力学，因此单分子速率常数与时间有关。分子的非随机激发可能会导致短期的表观非RRKM动态。对于旋转激活，特定J的2J + 1 K级别可能会高度混合，从而使K成为主动自由度，或K可能是一个好的量子数和一个绝热的自由度。非统计动力学对于双分子反应及其中间体以及双分子和单分子反应的产物能量分配通常很重要。过渡后的状态动态通常是高度复杂且非统计的。