Knowledge Bank

The ground electronic states of neutral and ionized diatomic silver and gold and the mixer dimer AgAu are investigated by ab initio self-consistent field and configuration interaction calculations. Relativistic effective potentials are employed to replace a defined number of core electrons in the $atoms\circ$. Basis sets comprised of Slater-type functions describe the valence electrons. Electronic properties of each species are calculated and compared to experiment, other effective potential calculations and non-relativistic all-electron calculations. Bond lengths and dissociation energies for $Ag2,Au2$, and AgAu were computed at the CI level to be 2.76{\AA}, 1.17eV, 2.68{\AA}, 1.68eV, 2.63{\AA}, and 2.31eV, respectively. The calculated equilibrium bond lengths are found to agree with experiment to about 0.1 {\AA}. It is speculated that the differences between the calculated and experimental values of bond lengths are due to a lack of f-type functions and additional d-and p-type functions in the basis and the omission in the CI procedures of configurations corresponding to all double excitations out of the d shell.