A method to calculate vibrational frequency shifts in heteroclusters: application to N2+–Hen

Abstract

A method is proposed whereby vibrational frequency shifts can be calculated in weakly bound heteroclusters and is applied to the ionic N₂⁺–He_n clusters. We use diffusion Monte Carlo to simulate the 3n degrees of freedom of the N₂⁺–He_n interactions while the N–N vibrational motion is solved by an adiabatic method. In addition, we report minimum energy structures, vibrationally averaged structures and binding energies for N₂⁺–He_n clusters for n= 1–12.