PYATB: An Efficient Python Package for Electronic Structure Calculations Using Ab Initio Tight-Binding Model

We present PYATB, a Python package designed for computing band structures and related properties of materials using the ab initio tight-binding Hamiltonian. The Hamiltonian is directly obtained after conducting self-consistent calculations with first-principles packages numerical atomic orbital (NAO) bases, such as ABACUS. comprises three modules: Bands, Geometric, Optical. In Bands module, one can calculate essential structures, including partial density states (PDOS), fat bands, Fermi surfaces, Weyl/Dirac points. unfolding method utilized to obtain energy spectra supercell by projecting electronic structure onto Brillouin zone primitive cell. With Geometric compute Berry phase curvature-related quantities, electric polarization, Wilson loops, Chern numbers, anomalous Hall conductivities. Optical module offers range optical property calculations, conductivity nonlinear responses, shift current curvature dipole.