Ab initio study of molecular surface electrostatic potential of hydrogen fluoride clusters (HF)n, (n=2–15)

Hydrogen-bonded clusters of hydrogen fluoride (HF)n(n=2–15), have been studied at Hartree–Fock level using the 6-31G basis set. Generated wavefunctions were used to calculate the electrostatic potential V(r) on the cluster surfaces. Calculated physical properties are expressed quantitatively in terms of molecular surface area, volume and three statistically based quantities obtained from the surface electrostatic potential. The maxima and minima in the potentials VS,min(r), VS,max(r) have predicted the sites and directionality of the H bonding in the cluster. The energy of the HOMO of the clusters correlates linearly with its VS,min. Energy gaps between frontier orbitals, εHOMO–LUMO have been discussed as a measure of cluster reactivity.