Two-Component Calculations of Spin-Orbit Effects for a van der Waals Molecule Rn_2

摘要

Electronic structures of the weakly bound Rn_2 were calculated by the two-component Moller-Plesset second-order perturbation and coupled-cluster methods with relativistic effective core potentials including spin-orbit operators. The calculated spin-orbit effects are small, but depend strongly on the size of basis sets and the amount of electron correlations. Magnitudes of spin-orbit effects on D_e (0.7-3.0 meV) and R_e (-0.4 approx -2.2 A) of Rn_2 are comparable to previously reported values based on configuration interaction calculations. A two-component approach seems to be a promising tool to investigate spin-orbit effects for the weak-bonded systems containing heavy elements.