A rigid-ion pair potential developed for a-Fe2O3 (hematite). The energy between two ions is partitioned into a long-range Coulombic interaction and a short-range one that describes Pauli repulsions and van der Waal’s attractions. The short-range term is modelled by the Buckingham potential. It is the group of parameters denoted as "set 1" in the publication of Vaari in Solid State Ionics 270 (2015) 10–17.