Long-range three-body atom-diatom potential for doublet Li${}_3$

TL;DR

This paper presents an accurate long-range potential energy surface for the lithium trimer in the ground state, using high-level ab initio calculations and dispersion corrections, relevant for understanding three-body interactions.

Contribution

It provides the first detailed long-range potential energy surface for the Li3 molecule, including dispersion coefficients and damping terms, derived from high-accuracy ab initio methods.

Findings

Accurate long-range potential energy surface for Li3 established

Dispersion coefficients and damping terms characterized

Surface accurately represents three-body interactions at large distances

Abstract

An accurate long-range {\em ab initio} potential energy surface has been calculated for the ground state ${}^2A'$ lithium trimer in the frozen diatom approximation using all electron RCCSD(T). The {\em ab initio} energies are corrected for basis set superposition error and extrapolated to the complete basis limit. Molecular van der Waals dispersion coefficients and three-body dispersion damping terms for the atom-diatomic dissociation limit are presented from a linear least squares fit and shown to be an essentially exact representation of the {\em ab initio} surface at large range.