FIG. . The critical network of the electron density of a benzene molecule, evaluated by post-processing the maximum spanning tree on a Delaunay triangulation according to the algorithms given in section II F. The bond that was filled in by the gap-filling algorithm is shown in red; the remaining black lines are the pruned maximum spanning tree. To improve the smoothness of the bonds, the DFT grid used for this plot contains around twice the number of gridpoints as the coarser grids used in the rest of this work. The axes are in bohr.