title: A first-principles study on the existence and structures of the lighter alkaline-earth pernitrides.
abstract: The lighter alkaline-earth pernitrides BeN(2), MgN(2), and CaN(2) have been structurally predicted by a series of density-functional (GGA/PBE/PAW) electronic-structure calculations. Despite their crystal chemistry clearly pointing towards the formulation M(2+)N(2)(2-) with an N-N distance of 1.26 A, all phases turn out as metallic compounds which are exothermic with respect to the elements. The M(2+) coordination numbers are a simple function of the cationic radius. The bulk moduli are about three times smaller than those of the noble-metal pernitrides, a consequence of the smaller anionic charge in the former phases.
authors.affiliation: RWTH Aachen University, Institute of Inorganic Chemistry, Landoltweg 1, 52056 Aachen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Wessel
authors.forename: Richard
authors.initials: R
authors.lastname: Dronskowski