On the ground states of copper, silver and gold silicides

The results of a theoretical investigation of the ground states of SiCu, SiAg and SiAu are presented. Calculations were carried out using high-level correlated methods including relativistic corrections. The theoretical results are compared with the results of recent experimental studies of these molecules. It has been concluded from the experimental data that the ground states of SiCu, SiAg and SiAu are 2Σ. Both non-relativistic and relativistic calculations predict the electronic ground state of these molecules to be 2Π and that it lies at least by 0.5 eV lower than all other states.