DiracBilinears.jl: A package for computing Dirac bilinears in solids

DiracBilinears.jl is a Julia package for computing Dirac bilinears, which are fundamental physical quantities of electrons in relativistic quantum theory, using first-principles calculations for solids. In relativistic quantum theory, 16 independent bilinears can be defined using the four-component Dirac field. To focus on the low-energy physics typically considered in condensed matter physics, we consider the bilinears represented by the non-relativistic two-component Schrödinger field, obtained from the 1 / m expansion to leading order. This package can evaluate the spatial distributions and Wannier matrix elements of the Dirac bilinears in solids quantitatively by connecting to the external first-principles calculation packages, including Quantum ESPRESSO, Wannier90, and wan2respack. Program Title: DiracBilinears.jl CPC Library link to program files: https://doi.org/10.17632/j57y5cjkmc.1 Developer's repository link: https://github.com/TatsuyaMiki/DiracBilinears.jl.git Licensing provisions: GNU General Public License 3.0 Programming language: Julia External software: Quantum ESPRESSO , Wannier90 , wan2respack Nature of problem: In relativistic quantum theory, Dirac bilinears are the fundamental physical quantities derived from the Dirac field. This package is a tool for the evaluation of the bilinears in solids quantitatively. Solution method: This package evaluates the non-relativistic expression of Dirac bilinears, focusing on the low-energy regime typically discussed in condensed matter physics. It uses results from first-principles calculations performed with Quantum ESPRESSO , Wannier90 , and wan2respack . By using the Bloch wave functions and the Wannier functions obtained from these packages, this package computes spatial distributions and Wannier matrix elements of the bilinears. Additional comments including restrictions and unusual features: This package requires Quantum ESPRESSO calculations using norm-conserving pseudopotentials and supports wan2respack in “spinor” branch on GitHub. 1 .