Electronic structure interpolation via atomic orbitals

TL;DR

This paper introduces an efficient and accurate method for electronic structure interpolation using optimized atomic orbitals, which are systematically improvable and applicable to complex systems, outperforming existing schemes in transferability and robustness.

Contribution

The authors develop a new atomic orbital-based interpolation scheme that is easy to implement, robust, and more transferable than previous methods, suitable for metallic and complex systems.

Findings

Achieves about 10 meV accuracy with 16-25 orbitals per atom.

Works effectively for metallic systems and complex band structures.

Offers better transferability than Shirley's basis and Wannier functions.

Abstract

We present an efficient scheme for accurate electronic structure interpolations based on the systematically improvable optimized atomic orbitals. The atomic orbitals are generated by minimizing the spillage value between the atomic basis calculations and the converged plane wave basis calculations on some coarse $k$-point grid. They are then used to calculate the band structure of the full Brillouin zone using the linear combination of atomic orbitals (LCAO) algorithms. We find that usually 16 -- 25 orbitals per atom can give an accuracy of about 10 meV compared to the full {\it ab initio} calculations. The current scheme has several advantages over the existing interpolation schemes. The scheme is easy to implement and robust which works equally well for metallic systems and systems with complex band structures. Furthermore, the atomic orbitals have much better transferability than the Shirley's basis and Wannier functions, which is very useful for the perturbation calculations.