The theory of atoms in molecules has been applied to study the proximity effect in a series of 14 dimethoxyethers of formula CH 3 O(CH 2 ) n OCH 3 (n=1–14). The empirical relationships that stem from both the dependence of atomic populations with the error integral and the atomic energies with the size of the molecule, together with the statistical analysis of the remaining atomic and bond properties, highlight that the presence of two oxygen atoms in a diether only gives rise to specific CH 2 groups when n≤4. The modification of the methylene charge distribution is negligible for further distances. These results agree with previous findings obtained within the framework of molecular models of non electrolyte solutions.