For the past 15 years, the OpenKIM cyberinfrastructure has provided the atomistic simulation community with a curated repository of interatomic potentials (IPs) tested for coding integrity and material property predictions, as well as an API to manage IPs and deploy them in popular simulation codes. In the past, the OpenKIM property tests have been limited to a single chemical element each. While many insights into IP predictions of metal and semiconductor behavior can be gleaned from single-element tests, it is obvious that properties of multi-element crystalline materials must also be calculated to evaluate an IP’s performance. To address this need, we have developed Crystal Genome — a framework for property testing of crystals of arbitrary structure and composition.
Crystal Genome adopts the AFLOW crystal prototype standard to classify arbitrary crystals in a succinct, human-readable manner. For thousands of crystals classified in this manner, we have developed tests for equilibrium crystal structure and elastic constants, with plans for more properties to come. Additionally, we have taken this opportunity to extend the OpenKIM API and property testing framework to support bonded force fields, whereas previously only reactive IPs were supported. This support is enabled through the new LAMMPS type labels framework and allows for automatic comparisons between reactive IPs, bonded force fields, and reference data archived in OpenKIM.