Fig. 5. Charge distribution around K⋯K pairs shown by isosurfaces (cutoff = 0.001 e au⁻³) and integrated charge densities. (a)–(d) Blue regions indicate positive isosurface (electronic charge accumulation); red regions indicate negative isosurface (electronic charge depletion). The charge density of the K_a⋯K_a pair occupying ‘2a’ sites is shown along (a) a-, and (b) c-axes, and of the K_b⋯K_b pair occupying ‘2b’ sites is shown along (c) c-, and (d) a-axes. H₂O separates and coordinates with the K_a⋯K_a and K_b⋯K_b pairs. Integrated charge computed for the (e) K_a⋯K_a pair, (f) K_b⋯K_b pair. The insets in (e) and (f) compare the charge behavior in K_a⋯K_a and K_b⋯K_b pairs.