Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
J Chem Phys. 2011 Jul 28;135(4):044116. doi: 10.1063/1.3610957.
We present a new definition of the transition state for chemical reactions, named the χ(1) separatrix. In contrast to previous transition state definitions which depend on the choice of reaction coordinates, the χ(1) separatrix is defined by choosing a time scale for observation and is connected to exact rate constants in the high friction limit. We demonstrate that this separatrix appears in the isomerization of alanine dipeptide as a stationary population in quasi-equilibrium, without assuming a particular coordinate system or reactant and product surfaces.
我们提出了化学反应过渡态的一个新定义,命名为 χ(1)分离界线。与依赖于反应坐标选择的先前过渡态定义不同, χ(1)分离界线是通过选择观察的时间尺度来定义的,并且在高摩擦极限下与精确的速率常数相关联。我们证明了,在丙氨酸二肽的异构化中,这个分离界线以准平衡的固定群体出现,而不假设特定的坐标系或反应物和产物表面。