Local Energy Landscape in a Simple Liquid

TL;DR

This paper introduces a local energy landscape (LEL) concept limited to phase space, using molecular dynamics to relate local coordination to relaxation processes in simple liquids.

Contribution

It proposes a simplified local energy landscape framework based on coordination number, aiding understanding of liquid and glass behavior.

Findings

LEL correlates local coordination with energy excitations.

LEL captures beta-relaxation phenomena.

Useful for analyzing complex liquid and glass dynamics.

Abstract

It is difficult to relate the properties of liquids and glasses directly to their structure because of complexity in the structure which defies precise definition. The potential energy landscape (PEL) approach is a very insightful way to conceptualize the structure-property relationship in liquids and glasses, particularly on the effect of temperature and history. However, because of the highly multi-dimensional nature of the PEL it is hard to determine, or even visualize, the actual details of the energy landscape. In this article we introduce a modified concept of the local energy landscape (LEL) which is limited in phase space, and demonstrate its usefulness using molecular dynamics simulation on a simple liquid at high temperatures. The local energy landscape is given as a function of the local coordination number, the number of the nearest neighbor atoms. The excitations in the LEL corresponds to the so-called beta-relaxation process. The LEL offers a simple but useful starting point to discuss complex phenomena in liquids and glasses.