Topology maps of bond descriptors based on the kinetic energy density and the essence of chemical bonding.

Analysis of the kinetic energy density within a molecule identifies patterns in its electronic structure that are intuitively linked to familiar concepts of chemical bonding. The function ν(r), termed localized-orbital locator and based on the positive-definite kinetic energy density τ+, is employed to characterize classes of covalent bonds in terms of its full topology of all critical points of rank three. Not only does ν(r) reveal patterns in chemical bonding, it also discloses features and the influence of extended electronic cores. Gradient paths define the extension of the valence space around an atomic centre; they separate various core level regions from bonding domains, and partition molecules in sensible bonded subunits. Location and ν(r)-values of critical points add a quantitative aspect to the bond characterization; profiles of unconventional chemical linkages such as charge-shift bonds emerge in a natural way.