Molecular dynamics simulation of superionicity in Neighborite, NaMgF 3

Superionicity in neighborite, NaMgF 3 , has been studied by molecular dynamics using parameter‐free Gordon‐Kim potentials. These simulations show that this halide‐based perovskite has a superionic phase. The onset temperature for superionicity is ∼ 50–100 K below the melting point. This is a novel type of superionicity in a halide, occurring as it does in a perovskite rather than a fluorite. Superionicity is demonstrated to occur whether one uses the full ionicity for Mg 2+ and F − or employs reduced charges derived from a Quantum Chemistry calculation. The relevance of these findings to predictions of superionicity in the oxide perovskite MgSiO 3 [Matsui and Price, 1991] is discussed.