Function(ELF) electrophilic/nucleophilic sites Laplacian (∇ 2 ρ) atomic graph, electrophilic/nucleophilic sites Electrostatic Potential (φ ) interaction strengths w/ nuclei, other electrons Energy Density Valence shell polarization Delocalization Index (ε) π-character 13 ETA Index interaction type Localized Orbital Locator e localization Table A set of QTAIM features and how they have been interpreted in the past.