Ab initio-based potential energy surfaces and predicted microwave spectra of the Ar–I2(X1Σg+) Van der Waals complex

The ground state Ar–I2 potential energy surface has been calculated ab initio and scaled in two ways. The relative stabilities of the two ArI2 conformers (linear and T-shaped) are found to be different for the two cases. Predicted sets of microwave transitions associated with the two conformers are found to be similar, but the energies of the rotational levels associated with each conformer differ significantly for the two cases. This difference provides a possible means for direct experimental identification of the lowest energy structure of ArI2 in terms of its microwave spectrum.