Energetics of MnO[subscript 2] polymorphs in density functional theory

Abstract

We report the energetics and properties of the β, α, R, γ, λ, and δ polymorphs of MnO[subscript 2] within density functional theory, comparing the performance of the recently introduced SCAN functional with that of conventional exchange-correlation functionals and experiment. We find that SCAN uniquely yields accurate formation energies and properties across all MnO[subscript 2] polymorphs. We explain the superior performance of SCAN based on its satisfaction of all known constraints appropriate to a semilocal exchange-correlation functional and its accurate representation of all types of orbital overlap.