Long-range interactions in the ozone molecule: spectroscopic and dynamical points of view

TL;DR

This study characterizes long-range electrostatic and van der Waals interactions between oxygen atoms and molecules, calculating potential energy surfaces to aid understanding of ozone formation and low-energy collision processes.

Contribution

It provides detailed potential energy surfaces and interaction curves for O and O$_2$, including spin-orbit effects, advancing the modeling of ozone spectroscopy and dynamics.

Findings

27 electronic potential energy surfaces calculated

Potential energy curves for O–O$_2$ interactions determined

Results support modeling of ozone formation and collision processes

Abstract

Using the multipolar expansion of the electrostatic energy, we have characterized the asymptotic interactions between an oxygen atom O$(^3P)$ and an oxygen molecule O$_2(^3\Sigma_g^-)$, both in their electronic ground state. We have calculated the interaction energy induced by the permanent electric quadrupoles of O and O$_2$ and the van der Waals energy. On one hand we determined the 27 electronic potential energy surfaces including spin-orbit connected to the O$(^3P)$ + O$_2(^3\Sigma_g^-)$ dissociation limit of the O--O$_2$ complex. On the other hand we computed the potential energy curves characterizing the interaction between O$(^3P)$ and a O$_2(^3\Sigma_g^-)$ molecule in its lowest vibrational level and in a low rotational level. Such curves are found adiabatic to a good approximation, namely they are only weakly coupled to each other. These results represent a first step for modeling the spectroscopy of ozone bound levels close to the dissociation limit, as well as the low energy collisions between O and O$_2$ thus complementing the knowledge relevant for the ozone formation mechanism.