Nearest-Neighbor Broken Bond Model for Describing the Surface Energies of Transition Metals

TL;DR

This paper extends the nearest-neighbor broken bond model to describe surface energies across various transition metals, demonstrating linear relationships and calculating bond energies, thus broadening its applicability.

Contribution

It verifies the NNBB model's generality for multiple transition metals and provides a method to determine bond energies from surface data.

Findings

Linear relationships between surface energies and missing bonds for all studied metals.

Bond energies for different metals are obtained through model fitting.

Model accurately describes surface energies across transition metals.

Abstract

In our recent works, we used a nearest-neighbor broken bond (NNBB) model to fit the surface energy of Pt, Pd, and Au surfaces [Adv. Theory Simul. 1800127 (2018)]. It was verified that this model could describe the surface energies of above noble metals with high accuracy. The applications of this model in real-time simulations of equilibrium nanocrystal transformations are in good agreements with the experimental observations at macroscopic time scales quantitatively. In this work, we want to further verify the generality of the NNBB model for other transition metals. All surface tentions and lattice constants were extracted from the database of Materials Project. The number of missing NN bonds of different slabs from low-index surfaces to open surfaces were counted for both surface atoms and subsurface atoms. As presented below, linear relationships between surface energies and missing bonds number are found for all studied elements. The bond energies for different metals are obtained through fitting NN bonds and surface energy of different surfaces.