MEAM interatomic potential for thermodynamic and mechanical properties of lithium allotropes

Abstract

Li has relatively simple electronic structure but exhibits complex allotropic phase transitions. Atomistic modeling is important to reveal thermodynamic and mechanical properties at grain and interface scales in multi-phase Li. However, extant interatomic potentials have limited accuracy in reproducing properties in the FCC, BCC and HCP phases of Li. Here, we develop a new interatomic potential for multi-phase Li using the classical MEAM approach. The new potential is fit to key properties of all three phases based on both extant and new DFT calculations. An extensive range of simulations are performed to validate the new potential. Good accuracy and transferability are demonstrated in all three phases and over a wide range of temperatures. The current potential is thus suitable for modeling both thermodynamic and mechanical behavior of Li and can be applied generally in a wide range of applications.