MagneticKP: A package for quickly constructing $\boldsymbol{k}\cdot\boldsymbol{p}$ models of magnetic and non-magnetic crystals

TL;DR

MagneticKP is a software package that provides a fast and versatile method for constructing effective $oldsymbol{k}oldsymbol{ ext{·}}oldsymbol{p}$ Hamiltonians for magnetic and non-magnetic crystals, applicable to both spinless and spinful systems.

Contribution

It introduces an efficient algorithm for constructing $oldsymbol{k}oldsymbol{ ext{·}}oldsymbol{p}$ models, significantly improving speed and flexibility over previous methods, and implements it in the MagneticKP package.

Findings

The algorithm is much faster than previous methods.

It works for both magnetic and nonmagnetic systems.

It can generate Hamiltonians around arbitrary momentum points.

Abstract

We propose an efficient algorithm to construct $\boldsymbol{k}\cdot \boldsymbol{p}$ effective Hamiltonians, which is much faster than the previously proposed algorithms. This algorithm is implemented in MagneticKP package. The package applies to both single-valued (spinless) and double-valued (spinful) cases, and it works for both magnetic and nonmagnetic systems. By interfacing with SpaceGroupIrep or MSGCorep packages, it can directly output the $\boldsymbol{k}\cdot \boldsymbol{p}$ Hamiltonian around arbitrary momentum and expanded to arbitrary order in $k$.