Designing a tuned hybrid density functional for accurate electronic, optical, and magnetic properties of CrSBr

CrSBr, a layered antiferromagnet, has attracted significant attention due to its desirable physicochemical properties, including ambient stability, relatively high Néel temperature, and strong coupling between excitons and magnons, among others. While experimental research on this material has progressed at a rapid pace, corresponding advances on the computational front have been slower, in part, due to the need for expensive self-consistent, many-body perturbation theory (MBPT) approaches to reproduce electronic and optical (excitonic) properties accurately. Here, we present an alternate approach—rooted in generalized Kohn-Sham (GKS) density functional theory—that can deliver accurate electronic bandstructures, optical absorption spectra, exciton binding energies, and magnon spectra of bulk and few-layer CrSBr at much lower computational cost relative to MBPT. Using a minimal two-parameter set that can be tuned to reproduce a few accurate experimental and/or theoretical benchmarks such as fundamental and optical gaps, we demonstrate excellent agreement across a broad range of optoelectronic and magnetic properties for this material. The approach presented here is readily generalized to other magnetic semiconductors, further advancing the utility of the GKS approach for these complex materials.