Interaction and Polarization Energy Relationships in σ-Hole and π-Hole Bonding

We demonstrate that a wide range of sigma- and pi-hole interaction energies can be related to (a) the electrostatic potentials and electric fields of the sigma- and pi-hole molecules at the approximate positions of the negative sites and (b) the electrostatic potentials and polarizabilities of the latter. This is consistent with the Coulombic nature of these interactions, which should be understood to include both electrostatics and polarization. The energies associated with polarization were estimated and were shown to overall be greater for the stronger interactions; no new factors need be introduced to account for these. All of the interactions can be treated in the same manner.