Fig. 4: Reaction mechanism to form O–O dimers in Li0.67MnO2F from ab inito molecular dynamics (AIMD) and geometry relaxations.

a O···O interatomic separation of O species forming O–O dimers from GGA+U AIMD simulations at 500 K. b Total energy of selected structures along the AIMD trajectory, fully relaxed with DFT using the HSE06 functional. c Geometry of the relaxed structures from b, indicating Mn migration events and O–O dimerisation. Mn ions displaced from their octahedrally coordinated rocksalt sites are indicated by pink polyhedra.