Boson Slave Solver (BoSS) v1.1

TL;DR

BoSS v1.1 is a software tool that efficiently models strongly correlated electron systems using the slave-boson method, applicable to extended Hubbard models including p-d interactions, with practical examples and integration with electronic structure codes.

Contribution

This work introduces BoSS v1.1, a new software implementation of the slave-boson method for extended Hubbard models, enabling accurate modeling of complex correlated materials.

Findings

Demonstrated band renormalization in SrVO3

Analyzed Ni 3d multiplet structures in LaNiO3

Explored magnetic moments and insulating behavior in SmNiO3

Abstract

Accurate and computationally efficient modeling of systems of interacting electrons is an outstanding problem in theoretical and computational materials science. For materials where strong electronic interactions are primarily of a localized character and act within a subspace of localized quantum states on separate atomic sites (e.g., in transition metal and rare-earth compounds), their electronic behaviors are typically described by the Hubbard model and its extensions. In this work, we describe BoSS (Boson Slave Solver), a software implementation of the slave-boson method appropriate for describing a variety of extended Hubbard models, namely $p-d$ models that include both the interacting atomic sites ("$d$" states) and non-interacting or ligand sites ("$p$" states). We provide a theoretical background, a description of the equations solved by BoSS, an overview of the algorithms used, the key input/output and control variables of the software program, and tutorial examples of its use featuring band renormalization in SrVO$_3$, Ni $3d$ multiplet structure in LaNiO$_3$, and the relation between the formation of magnetic moments and insulating behavior in SmNiO$_3$. BoSS interfaces directly with popular electronic structure codes: it can read the output of the Wannier90 software package which postprocesses results from workhorse electronic structure software such as Quantum Espresso or VASP.