Quantum interference scattering of aligned molecules: Bonding in O4 and role of spin coupling

Abstract

Molecular beam experiments on collisions between oxygen molecules were performed at low energy and high angular resolution to permit observation of the “glory” interference effect. A novel technique for aligning the rotational angular momentum of the colliding molecules is exploited. Analysis of total scattering cross section data yields for the O2—O2 bond an energy of 1.65±0.08kJmol−1 for the most stable configuration (parallel molecules) at a distance of 0.356±0.007nm. These results indicate that most of the bonding in the dimer comes from electrostatic (van der Waals) forces but chemical (spin-spin) contributions are not negligible. © 1999 The American Physical Society.