Ab initio relativistic all-electron calculation of the Ar-I2 ground state potential

Correlated relativistic all-electron supermolecular ab initio calculations of the ground state potential of the Ar-I-2 molecule are presented. The role of differential intramonomer spin-orbit and correlation effects in the interaction energy is investigated and found to be only of minor importance. Two energetically very similar minima of the Ar-I-2 complex are found, corresponding to a linear and a T-shaped geometry of the monomers. The comparatively large isomerization barrier for the two conformations indicates the existence of two stable isomers at very low temperatures. (C) 1998 American Institute of Physics.