Supplemental Material

Geometries for one-electron systems, Energy curves of oneelectron systems, Error distribution of DFT and HF-DFT for 103 benchmark reactions, Table of energy difference between CCSD and CCSD(T) densities, Table of subset, systems, and stoichiometry information for the 103 benchmark reactions, Table of reaction indices of the 36 selected non-degenerated reactions, Table of ideal-DDE, pragmatic-DDE, and NDI of one-electron systems, Figures of density difference contour map between CCSD and CCSD(T), Figures of relationship between DDE and real-space density metrics