Four-body singlet potential energy surface for reactions of calcium monofluoride

TL;DR

This paper develops a detailed six-dimensional potential energy surface for the reaction between calcium monofluoride molecules, providing insights into the reaction mechanism relevant to ultracold chemistry.

Contribution

It constructs a full six-dimensional singlet potential energy surface for CaF + CaF reactions using high-level electronic structure calculations and Gaussian process interpolation.

Findings

Identifies a global minimum and a local minimum on the potential surface.

Reveals a barrierless transition state connecting minima.

Provides a basis for studying ultracold CaF chemistry.

Abstract

A full six-dimensional Born-Oppenheimer singlet potential energy surface is constructed for the reaction CaF + CaF $\rightarrow$ CaF$_2$ + Ca using a multireference configuration interaction (MRCI) electronic structure calculation. The {\it ab initio} data thus calculated are interpolated by Gaussian process (GP) regression. The four-body potential energy surface features one $D_{2h}$ global minimum and one $C_s$ local minimum, connected by a barrierless transition state that lends insight to the reaction mechanism. This surface is intended to be of use in understanding ultracold chemistry of CaF molecules.