Atom⋯atom RGBIs for (a) the PCLPYR dimer and (b) the XIZPON dimer that exhibit very similar interaction distances and different interaction angles. The interaction regions are marked with their RGBIs and the AIM topological parameters evaluated at the bcps. (c) The deformation electron-density map (0.005 a.u. surface) plotted for the linear dimer shows the effective interaction between the charge-depleted region of Br and the charge-concentrated region of N (lone-pair density). (d) The linear ∠C—Br⋯N experimental geometry in BCACEN (θx = 177.2°). (e) The perpendicular ∠C—Br⋯N hypothetical geometry in BCACEN (θx = 90°). Grey atoms are C, green Cl, blue N, gold Br and yellow S.