Direct Observation of the Geometry of Atom−Atom and Atom−Molecule Collisions

Abstract

We report crossed beam experiments on the laser assisted collisions Na(3s) + M + hν f Na(3p) + M with M ) Kr, N 2 , and CO 2 . By varying the photon polarization, we gain direct insight into the geometric properties of the collision complex. For the Na + Kr system, we are able to deduce from the experimental data the two possible directions (Condon vectors) of the internuclear axis at the moment of the optical transition.

Electronic structure of the NaN2 and NaC2H2 collision complexes: Experiment and theory

“…3 This has turned out to be close to exact for atom-atom optical collisions. 15 The optical transition occurs at a configuration R c of the nuclei, for which the resonance condition…”

“…In the atomic case, the weight factor p n for the first trajectory is typically by a factor of 2 larger than that for the second one, and therefore the Condon point on the incoming trajectory governs the alignment tensor. 3,15 In view of the similarity of the trajectories in all three cases, we expect a similar behavior for the molecular targets, that is, a larger weight for the first group of trajectories. Correspondingly, two examples for the first group are shown and only one for the second one.…”

Collisions of excited Na atoms with N2, C2H2and N2O molecules. Surface-hopping calculation of the Na(3p) fine structure population

“…Optical collisions are scattering processes where the projectile is optically excited during its interaction with the target. This paper is concerned with the optical collision experiments of Na atoms with a series of molecules which have been carried out in the past few years by Grosser and coworkers [1][2][3] following similar experiments with atomic targets. 1,4,5 The experiments can briefly be explained as follows.…”

“…This paper is concerned with the optical collision experiments of Na atoms with a series of molecules which have been carried out in the past few years by Grosser and coworkers [1][2][3] following similar experiments with atomic targets. 1,4,5 The experiments can briefly be explained as follows. The collisions take place in a crossed beam arrangement.…”

Potential Energy Surfaces for the Na(3p)N2, Na(3p)HCN and Na(3p)C2H2 Complexes:Ab Initio Calculations and Model Considerations

“…The experiments are carried out with polarized laser light and, therefore, probe not only the energy difference as a function of the mutual arrangement of the colliding complex but also the orientation of the transition dipole of the optical excitation. In this way, a spatial picture of the collisional process and the alignment of the 3p orbital in the final state can be obtained [6]. Let us note that the transition may take place before or after the closest encounter of the colliding particles.…”