Accurate Simulation of Surfaces and Interfaces of Face-Centered Cubic Metals Using 12−6 and 9−6 Lennard-Jones Potentials

Abstract

Molecular dynamics and Monte Carlo simulations often rely on Lennard-Jones (LJ) potentials for nonbond interactions. We present 12−6 and 9−6 LJ parameters for several face-centered cubic metals (Ag, Al, Au, Cu, Ni, Pb, Pd, Pt) which reproduce densities, surface tensions, interface properties with water and (bio)organic molecules, as well as mechanical properties in quantitative (<0.1%) to good qualitative (25%) agreement with experiment under ambient conditions. Deviations associated with earlier LJ models have been reduced by 1 order of magnitude due to the precise fit of the new models to densities and surface tensions under standard conditions, which also leads to significantly improved results for surface energy anisotropies, interface tensions, and mechanical properties. The performance is comparable to tight-binding and embedded atom models at up to a million times lower computational cost. The models extend classical simulation methods to metals and a variety of interfaces with biopolymers, surfactants, and other nanostructured materials through compatibility with widely used force fields, including AMBER, CHARMM, COMPASS, CVFF, OPLS-AA, and PCFF. Limitations include the neglect of electronic structure effects and the restriction to noncovalent interactions with the metals.