Pressure modulates the phase stability and physical properties of zinc nitride iodine
To explore new stable phases in metal nitride halides, the structural, electronic and optical properties, and chemical bonding characteristics of Zn2NI under pressure were studied on the basis of crystal structure predicting evolution and density function calculations. Three new high-pressure phases of Zn2NI were revealed: Pna21 and Pnma-II phases with NZn4 tetrahedrons, and P63/mmc phase with NZn6 polyhedrons above 6, 23, and 94 GPa, respectively. The calculated electronic structures of all the phases of Zn2NI under pressure indicated that they are all semiconductors except P63/mmc phase. Therefore, pressure can simulated Zn2NI a transition from a semiconductor to a metal. The optical properties (e.g., absorption coefficient, dielectric function) of these high-pressure phases were also discussed.