Three-body interactions involving clusters and films

TL;DR

This paper investigates how three-body interactions, specifically the ATM triple dipole interaction, vary significantly with geometry and atomic species in clusters and films, affecting the total energy contributions.

Contribution

It demonstrates that three-body interaction contributions can be much larger or smaller than previously thought, depending on geometry and atomic properties, and establishes systematic trends.

Findings

Three-body interaction contributions vary widely with geometry.

For certain geometries, three-body energy can be comparable to two-body energy.

The sign of three-body energy can be attractive or repulsive depending on conditions.

Abstract

The three body (triple dipole) interaction of Axilrod, Teller and Muto (ATM) contributes 5 to 10 % of the total energy of condensed phases of inert elements. It is shown in this paper for clusters and films that a much larger or smaller ATM contribution can arise for other geometries or other atomic species. The ratio R of the three body interaction energy to the two body energy is evaluated for a wide variety of configurations. This ratio varies considerably with the geometry. For highly polarizable atoms in certain geometries, the magnitude of the three body energy is comparable to that of the two body energy and can be either attractive or repulsive. Systematic trends are established and explained.