title: A theoretical study of nitrogen-rich phosphorus nitrides P(Nn)m.
abstract: Ab initio calculations predict that structures P(Nn)m (n = 3, 4; m = 1-4; with linear N3, tetrahedral N4, and square N4) correspond to local energy minima characterized by having real frequencies for all eigenvectors of the Hessian matrix. The central P atom often prefers having an odd number of bonds, although we also found some stable structures where P is evenly bonded. The special role of the phosphorus atom in the geometrical arrangements of the P(Nn)m systems was investigated. The low barriers of P(N4)m in the gas-phase decomposition reactions mean that these nitrogen-rich systems require external stabilization if they are to be used as high-energy density materials or starting materials for further syntheses.
authors.affiliation: Department of Chemistry, Scientific Modeling and Simulation Laboratory (SMSL), Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X7, Canada.
authors.forename: Lijie
authors.initials: L
authors.lastname: Wang
authors.forename: Peter L
authors.initials: PL
authors.lastname: Warburton
authors.forename: Paul G
authors.initials: PG
authors.lastname: Mezey