Figure 1

Isometric representation of unit cells used for ReaxFF reparameterization database generation and validation simulation boxes. The left column shows unit cells of LiF stable (a) and metastable phases (b,c) corresponding to face-centered cubic (FCC), hexagonal (HEX), and body-centered cubic (BCC) lattice types with space groups \({\text{Fm}}\bar{3}{\text{m}}\), \({\text{Pm}}\bar{3}{\text{m}}\), and \({\text{P6}}_3{\text{mc}}\) respectively⁵⁹. The right column displays atomistic systems used for testing the improved force field built as supercells of the stable unit cell (a): equal Li-F atoms (d), 10% vacancies at Li sites (e), and 10% interstitial Li atoms (f). The shown renderings were generated using the Visual Molecular Dynamics (VMD) code⁷⁵ and followed the Corey–Pauling–Koltun (CPK) colouring scheme⁷⁶.