Abstract

Density functional theory (DFT) in chemistry and materials science aims for “chemical accuracy,” but this goal is challenged by the need to approximate the exact exchange-correlation (XC) energy functional. The restored- regularized strongly constrained and appropriately normed (r²SCAN), meta-generalized gradient approximation to the XC functional fulfills 17 exact constraints of the XC energy, and has significantly boosted prediction accuracy for molecules and materials. However, r²SCAN remains inadequate at predicting the properties of open d and f transition-metal strongly correlated compounds, such as band gaps, magnetic moments, and oxidation energies. Prediction inaccuracies of r²SCAN energies arise from functional- and density-driven errors, mainly resulting from the DFT self-interaction error. Here, we propose a method termed r²SCANY@r²SCANX to mitigate the self-interaction error of XC functionals for the accurate simulations of electronic, magnetic, and thermochemical properties of transition-metal oxides. r²SCANY@r²SCANX uses different fractions of exact Hartree-Fock exchange, X for the electronic density and Y for the density functional approximation of the total energy, thereby simultaneously addressing functional-driven and density-driven inaccuracies. Building on just one (or maximum two) parameters that apply unchanged to s-p-bonded systems, we demonstrate that r²SCANY@r²SCANX improves upon the r²SCAN predictions for 20 highly correlated oxides and even out- performs the highly parametrized DFT(r²SCAN)+U method—the state-of-the-art approach to predict strongly correlated materials. Prediction uncertainties for oxidation energies and magnetic moments of transition- metal oxides are significantly reduced by r²SCAN10@r²SCAN50 and band gaps with r²SCAN10@r²SCAN. r²SCAN10@r²SCAN50 diminishes the density-driven error of the energy in r²SCAN and r²SCAN10. We demonstrate that the computationally efficient r²SCAN10@r²SCAN is nearly as accurate as the global hybrid r²SCAN10 for oxidation energies. This indicates that accurate energy differences can be obtained through rate-limiting self-consistent iterations and geometry optimizations with the efficient r²SCAN. Subsequently, a more expensive nonlocal functional, such as a hybrid or self-interaction correction, can be applied in a fast, single post-self-consistent calculation, as in r²SCAN10@r²SCAN.