Guberman Steven L
Institute for Scientific Research, 22 Bonad Road, Winchester, Massachusetts 01890, USA.
J Phys Chem A. 2007 Nov 8;111(44):11254-60. doi: 10.1021/jp070892q. Epub 2007 Jun 5.
Intermediate states formed during the dissociative recombination of molecular ions with electrons can play significant roles in determining the magnitude of the total rate coefficient. These resonances are Rydberg states of two types, that is, they can have the ground or excited states of the ion as a core. Those with the excited cores have a fundamentally different excitation mechanism than those with the ground state core. The importance of excited core states in dissociative recombination has received only limited attention in the literature. Theoretical calculations on the dissociative recombination of N2+ are reported which compare the two types of resonances. Potential curves, electronic widths, cross sections, and rate coefficients are calculated for dissociative recombination along the 2(1)Sigma(g)+ state, one of several routes for the dissociative recombination of N2+. The ground core resonances, in this example, are relatively unimportant compared to those with the excited core. Inclusion of the excited core resonances increases the rate coefficient by about a factor of 4 at room temperature, but the increase is not enough to establish 2(1)Sigma(g)+ as the dominant dissociative route.
分子离子与电子发生离解复合过程中形成的中间态，在决定总速率系数的大小方面可能发挥重要作用。这些共振是两种类型的里德堡态，也就是说，它们可以以离子的基态或激发态作为核心。具有激发态核心的共振与具有基态核心的共振相比，其激发机制有根本的不同。激发态核心态在离解复合中的重要性在文献中仅受到有限的关注。本文报道了对N2+离解复合的理论计算，比较了这两种类型的共振。沿着2(1)Σ(g)+态计算了离解复合的势能曲线、电子宽度、截面和速率系数，2(1)Σ(g)+态是N2+离解复合的几种途径之一。在这个例子中，与具有激发态核心的共振相比，基态核心共振相对不太重要。包含激发态核心共振会使室温下的速率系数增加约4倍，但增加幅度不足以使2(1)Σ(g)+成为主要的离解途径。
