High-pressure phases and structural bonding ofGe3N4

Abstract

The spinel structure of ${\mathrm{Ge}}_3{\mathrm{N}}_4$ is compared with that of $\beta -{\mathrm{Ge}}_3{\mathrm{N}}_4$ and a cubic defect zinc-blende structure recently considered possible for ${\mathrm{C}}_3{\mathrm{N}}_4.$ The $\beta$ phase is suggested to be a possible precursor phase to the spinel structure. Electronic structure calculations reveal that the spinel structure is a subtle extension of the defect zinc-blende phase in which the Ge atoms attempt to connect into the conventional zinc-blende structure.