Describing bond-breaking processes by reactive potentials

First nearest-neighbor models are routinely used for atomistic modeling of covalent materials. Neighbors are usually determined by looking for atoms within a fixed interaction range. While these models provide a faithful description of material properties near equilibrium, the limited interaction range introduces problems in heterogeneous environments and when bond-breaking processes are of concern. We demonstrate in this Rapid Communication that the reliability of reactive bond-order potentials is substantially improved by using an environment-dependent first nearest-neighbor definition.