Surface d0 half-metallicity of rocksalt MgN from first-principles

► Surface stabilities of the (1 1 1) and (0 0 1) surfaces of half-metallic rocksalt MgN. ► Half-metallicity is preserved at the (0 0 1) and the N-terminated (1 1 1) surfaces. ► Different electronic structure and magnetism: (1 1 1) versus (0 0 1) surfaces of rocksalt MgN.