title: Chemical bonding in group III nitrides.
abstract: We analyze in this article the evolution of the chemical bonding in group III nitrides (MN, M = Al, Ga, In), from the N-N bond dominated small clusters to the M-N bond dominated crystals, with the aim of explaining how the strong multiple bond of N(2) is destabilized with the increase in coordination. The picture that emerges is that of a partially ionic bond in the solid state, which is also present in all the clusters. The covalent N-N bond, however, shows a gradual decrease of its strength due to the charge transfer from the metal atoms. Overall, Al clusters are more ionic than Ga and In clusters, and thus the N-N bond is weakest in them. The nitrogen atom charge is seen to be proportional to the metal coordination, being thus a bond-related property, and dependent on the M-N distance. This explains the behavior observed in previous investigations, and can be used as a guide in predicting the structures and defects on semiconductor quantum dot or thin film devices of these compounds.
authors.affiliation: Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, 33006-Oviedo, Spain.
authors.forename: Aurora
authors.initials: A
authors.lastname: Costales
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Blanco
authors.forename: Angel
authors.initials: A
authors.lastname: Martín Pendás
authors.forename: Anil K
authors.initials: AK
authors.lastname: Kandalam
authors.forename: Ravindra
authors.initials: R
authors.lastname: Pandey