Energy band genesis from sublattice states in MgSiN2 and MgGeN2 crystals

The electronic structure of MgSiN₂ and MgGeN₂ orthorhombic crystals and their sublattices was analyzed at the density functional theory level using the sublattice method. The energy-band structure of the orthorhombic crystals is compared to the structure of their hypothetic analogues with the chalcopyrite lattice. The origin of the specific features of the valence band structure from the sublattice states is determined in the studied crystals, which is mainly due to the interaction of atoms in SiN₄ and GeN₄ cation tetrahedra.