SPECTROSCOPIC PROPERTIES FOR THE GROUND-STATES OF AUF, AUF+, AUF2, AND AU2F2 - A PSEUDOPOTENTIAL SCALAR RELATIVISTIC MOLLER-PLESSET AND COUPLED-CLUSTER STUDY

Accurate spectroscopic properties are given for the molecules AuF, AuF +, and AuF2 derived from relativistic coupled-cluster calculations using an energy-adjusted relativistic pseudopotential for gold. Nonrelativistic and relativistic second-order Møller-Plesset calculations are carried out for the dimer Au2F2 to investigate its stability in gas phase and to estimate the solid state stability of AuF. Relativistic effects are discussed for AuF at the coupled-cluster level by comparison with nonrelativistic results. For some of the properties relativistic effects are larger than electron correlation contributions leading to anomalies in the trend down the group 11 series of fluorides. Electric properties are calculated using the finite field method. Vibrational effects on molecular properties are discussed. The AuF coupled-cluster dissociation energy of 3.1 eV is in excellent agreement with the best estimate of Schwarz et al. [Angew. Chem. Int. Ed. Engl. 33, 212 (1994)] obtained from recent mass spectrometric studies (3.2 eV). The thermodynamic stability of AuF is discussed in detail. The calculated data suggest that AuF is not thermodynamically stable towards disproportionation into Au and AuF3. © 1995 American Institute of Physics.