Molecular Dynamics Investigations of the Melt‐Quenched Phase of Mg‐Doped Li‐Rich Anti‐Perovskite

Molecular dynamics simulation emulating the conventional melt-quenching technique is carried out to investigate the local structural and dynamical properties of Mg-doped Li-rich anti-perovskites, Li_2.8Mg_0.1OCl. The melt-quenched structure stabilizes in the native cubic phase of ABX₃, with a volume expansion of about 6.3%. While LiCl, Li₂O, or MgCl₂ phases are absent, sub-nanoscopic MgO_m moieties are found dispersed in the matrix. The defect-rich cubic phase of the quench has a substantial amount of positionally disordered Cl and O sites. The Li⁺ mobility in the matrix is found to be very close to that of the ideal crystalline phase.