Treatment of symmetry in the tight-binding method for crystals with several atoms per unit cell

Consistent treatment of symmetry in the tight-binding method, developed by Egorov et al [Phys. Stat. Sol. 26, 391 (1968)] for crystals with two atoms per unit cell, is generalized to crystals with several atoms per unit cell. A method is presented for expressing the matrix components of the tight-binding Hamiltonian in terms of independent parameters using group-theoretical techniques. The method is demonstrated by obtaining an analytical form for the low-dimensional effective Hamiltonian describing the electronic structure of the 2H-TaSe2 conduction band with quasi 2D hexagonal crystal structure.

Automated summary

The tight-binding method, initially designed for crystals with two atoms per unit cell, is extended to crystals with multiple atoms per unit cell. A technique based on group theory is introduced to express the matrix components of the tight-binding Hamiltonian in terms of independent parameters. This approach is demonstrated by obtaining an analytical form of the low-dimensional effective Hamiltonian for the conduction band of 2H-TaSe2 with quasi 2D hexagonal crystal structure.