Non-additive behavior of van der Walls dispersion forces due to material and surface geometry effects

TL;DR

This paper demonstrates that van der Waals forces exhibit non-additive behavior influenced by geometry and material properties, challenging traditional additive models and providing a versatile numerical method for complex 3D interactions.

Contribution

It introduces a general, accurate, and fast numerical method to study non-additive vdW interactions in arbitrary 3D geometries, revealing effects overlooked by traditional additive approaches.

Findings

Dispersion forces show non-additivity due to geometry and material effects.

Traditional additive models like LJ and PFA are contradicted by these results.

The method enables detailed analysis of normal, lateral, and rotational vdW forces.

Abstract

We present a series of calculations of van der Waals (vdW) forces that show non-additive behavior. The results reveal effects of geometrical dependences of the dispersion forces, that are in strong contradictions to the results from additivity approaches like the Lennard-Jones (LJ) pairwise interaction and the proximity force approximation (PFA). For the simple geometries treated here deviations appear when the effects of the materials are taken into account. We obtain these results with a general and simple numerical method that allows for a detailed study of the vdW interactions. The method is also accurate and fast, and due to its generality makes the study of interactions between three-dimensional (3D) objects, with arbitrary geometries and configurations, feasible. We present results for normal, lateral and rotational forces.