Scaling in Molecular Electronic Spectroscopy: Core-Nonpenetrating Rydberg States

实验物理化学计划支持教授罗伯特W。 马萨诸塞州理工学院的菲尔德在他的继续 “标度律”的研究，量子的先验已知函数 号码这种比例定律出现时，部分之间的耦合， 分子变得足够弱。例如， 类氢本征态可以表示为Z，n和 L.许多基于原子的缩放关系仍然是有用的和有指导意义的， 甚至对于多原子分子，对于非穿透核的分子里德伯 态，其中Rydberg电子与分子之间的耦合 离子核是非常弱的，类似氢系统是相当 强壮. 菲尔德将进行各种类型的实验， 共振增强多光子电离或多重共振 光谱学，努力开发实验方法， 核非穿透分子里德伯态的光谱研究。 这些研究将产生关于电各向异性的信息， 分子离子核的极化率。 关于这些实验的实际意义的一些评论是 有正当理由 为什么我们要关心 阳离子？ 所有的+1阳离子都有相同的电荷，所以这个主要的方面 阳离子与外界的相互作用是独立的 分子。 另一方面，离子特异性长程相互作用， 从较高的多极子（及其正常坐标）导出 位移导数）。 这些多极和衍生物控制着 共振长程离子分子，离子电子， 以及可能的离子-表面能量和角动量交换。 的 从岩心非穿透系统研究中获得的信息 里德伯态将对各种各样的 发生在等离子体中的过程。

The Experimental Physical Chemistry Program supports Prof. Robert W. Field of Massachusetts Institute of Technology in his continuing investigation of `scaling laws,` a priori known functions of quantum numbers. Such scaling laws arise when the coupling between parts of a molecule becomes sufficiently weak. For example, many properties of hydrogenic eigenstates can be expressed as simple functions of Z, n and l. Many atom-based scaling relationships remain useful and instructive, even for polyatomic molecules; for core-nonpenetrating molecular Rydberg states, in which the coupling between Rydberg electron and the molecular ion-core is very weak, the resemblance to hydrogenic systems is quite strong. Field will undertake various types of experiments involving either resonance-enhanced multiphoton ionization or multiple resonance spectroscopies in an effort to develop experimental methods for spectroscopic studies of core-nonpenetrating molecular Rydberg states. These studies will yield information on the electric anisotropies and polarizabilities of molecular ion cores. A few comments about the practical significance of these experiments are warranted. Why should we care about the electric multipole moments of cations? All +1 cations have the same monopole, so this dominant aspect of the interaction of the cation with the outside world is independent of the molecule. Ion-specific long-range interactions, on the other hand, derive from the higher multipoles (and their normal coordinate displacement derivatives). These multipoles and derivatives control the mechanisms and rates of resonant long-range ion-molecule, ion-electron, and possibly ion-surface energy and angular momentum exchange. The information obtainable from systematic studies of core-nonpenetrating Rydberg states would yield valuable insights into a wide variety of processes occurring in plasmas.