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Roughly ELI\u2010D (${{\\rm \\gamma} {{s\\hfill \\atop D\\hfill}}}$) in position space can be regarded as a quasi\u2010continuous weighted electronic charge distribution\u03c1\u03c3(the \u03c3\u2010spin electron density) where the weighting factor\u1e7cD(the so\u2010called pair\u2013volume function) is a local measure for the volume needed to build a same\u2010spin (spin \u03c3) electron pair:${{\\rm \\gamma} {{s\\hfill \\atop D\\hfill}}}$(r)=\u03c1\u03c3(r)\u00d7\u1e7cD(r) The values for ELI\u2010D are limited to the range of positive numbers. Typically ELI\u2010D values up to 2.5 (except for H atoms) can be found in the chemically relevant valence region for molecules. ELI\u2010D has been defined at explicitly correlated and at uncorrelated quantum chemical level. 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