Ab initio potential energy surface and intermolecular vibrational frequencies of C3–Ar complex

Abstract

The intermolecular potential energy surfaces for C3–Ar have been calculated by supermolecular CCSD(T) and MP4 methods. The MP4 and CCSD(T) potentials have similar global behaviours. Their global minima all correspond to the slightly distorted T-shaped geometries. From these two potentials, the intermolecular vibrational energies and wavefunctions were calculated. The energy level patterns of the vdW vibrational states were predicted for the C3–Ar complex. The zero point bending motion of this complex has a range of approximately 60°. The calculated transition frequencies of vdW bending agree well with available experimental data.