Electronic states of the copper silicide and its ions

Potential energy curves and spectroscopic parameters of the ground and exited states of SiCu, SiCu+, and SiCu− are presented. The calculations were performed by high-level correlated methods including the relativistic correction for the lowest states. The present results are compared with recent theoretical and experimental studies of SiCu and its ions and support the earlier theoretical conclusions concerning the assignment of the electronic ground state of SiCu. According to calculations presented in this paper the lowest energy states of SiCu, SiCu+, and SiCu−, are 2Πr, 1Σ+, and 3Σ−, respectively.