The ground state van der Waals potentials of the strontium dimer and strontium rare-gas complexes

The entire ground state potential energy curve of the strontium dimer is accurately described by the Tang-Toennies potential model defined by the three dispersion coefficients and two well parameters. The predicted vibrational frequency, anharmonicity, and vibration-rotation coupling constant are in excellent agreement with experiment. The Sr(2) reduced potential is almost identical to that of Ca(2) and Hg(2), providing further evidence to the conjecture that the van der Waals dimer potentials of group IIA and group IIB elements have the same shape, which is different from that of rare-gas dimers. The potentials of Sr-RG complexes (RG=He,Ne,Ar,Kr,Xe) are generated by the same potential model with its parameters calculated with combining rules. These potentials are shown to have the same shape which is between that of the strontium and rare-gas dimers.