A Simple Linear Relation Solves Unphysical DFT Energy Corrections

Material properties calculated using density functional theory (DFT) are often corrected to more closely match experimental values, but the most common correction method has flaws that lead to unphysical results and false positives in the material discovery process. In this work, we show that these flaws stem from the fact that only additive errors are considered, and we provide evidence that DFT predictions are likely subject to proportional error as well. We analyze the case of formation energy predictions since stability is a critical material property. We propose a simpler, linear formation energy correction method, which we call the 110\% PBE correction, that models proportional error and thereby addresses the problems associated with the most common correction method. We demonstrate that the conclusions drawn from the 110\% PBE correction method are more likely to be physically accurate.