Studying the Metal-Insulator Transition of VO₂ with GGA

Studying the metal-insulator transition (MIT) of VO₂ from first-principles generally requires the use of computationally expensive hybrid density functionals, while the less resource-intense functionals of the generalized gradient approximation (GGA) -type commonly fail to correctly describe the relative thermodynamic stabilities, crystal-, or electronic structures of the semiconducting and metallic monoclinic and rutile phases of VO₂. Unfortunately, investigating e.g. the effect of low-concentration doping on the VO₂ transition temperature requires simulation cell dimensions for which hybrid density functionals quickly become unfeasible. We present an overview of the underlying difficulties connected to the use of GGA functionals on the VO₂ MIT in commonly employed quantum chemistry codes and demonstrate that a computational setup using localized basis functions, pseudopotentials and a GGA functional with a small Hubbard correction helps achieving simultaneous description of qualitative band structure features, crystal geometries, and the MIT temperature of VO₂ correctly.