Abstract:
Nonrelativistic and scalar relativistic pseudopotential calculations were carried out for the isoelectronic series of diatomic molecules AuPt-, Au2, and AuHg+ at the Hartree-Fock, second-order Møller-Plesset (MP2), and coupled-cluster [CCSD(T)] level. For Au2 we performed large scale fully relativistic Dirac-Hartree-Fock and MP2 benchmark calculations in order to test the reliability of the pseudopotential approximation. Both methods yield almost identical spectroscopic properties for Au2. The comparison further reveals that pseudopotentials correctly describe the effects of relativity on the spectroscopic properties of Au2. The yet unknown diatomic species AuPt- and AuHg+ are stable compounds, and their rotational-vibrational constants are predicted. These show striking similarities compared to the values of Au2. MP2 results including a set of three g-functions per metal atom indicate that higher angular momentum functions are important for accurately predicting the bond distance of these molecules.
