Structure and interaction energies of the Ar…Cl2 complex. Application of first-order intermolecular potentials

The first-order intermolecular perturbation theory developed in the frame of a diatomics-in-molecule approach is used to calculate the potential energy surfaces for the Ar…Cl2 complex in the states which correlate with the X0g+(1Σ+) and B0u+ (3Π) states of the Cl2 fragment. Accurate vibrational calculations performed directly with these surfaces reveal close agreement with spectroscopic data.