No abstract

Ab initio calculations are performed to investigate the ground state properties, structural phase transition, electronic structure and mechanical properties of lithium nitride (Li 3 N), lithium imide (Li 2 NH) and lithium amide (LiNH 2). The computed ground state properties like equilibrium lattice constant, cell volume, valence electron density, cohesive energy, bulk modulus and its derivatives are in good agreement with available experimental data. The structural phase transitions from a-P6/mmm to b-P6 3 /mmc phase at a pressure of 17.5 GPa in Li 3 N and cubic (Fm3m) to hexagonal (P6 3 / mmc) phase at a pressure of 102 GPa in lithium imide (Li 2 NH) are observed. A new high pressure hexagonal (P6 3 /mmc) phase is predicted for Li 2 NH. Electronic structure reveals that Li 3 N and LiNH 2 are semiconductors, whereas Li 2 NH is an insulator. The calculated elastic constants indicate that these materials are mechanically stable at ambient condition.

No abstract

No abstract

No abstract