Relativistic and correlation study of coinage metal hydrides

The importance of relativistic effects on chemical and spectroscopic proper ties of molecules containing very heavy atoms is considered. The generation of the relativistic Gaussian basis sets for Cu, Ag and Au, for molecular r elativistic Dirac-Fock calculations is proposed. Nonrelativistic and relati vistic calculations were carried out for the (1)Sigma (+) electronic ground states of the coinage metal hydrides (CuH, AgH, AuH). The effects of relat ivity on the bond lengths, dissociation energies and parameters of vibratio nal-rotational spectra have been studied within a different accuracy of inc lusion of correlation effects. All calculations were performed with newly o ptimized relativistic Gaussian basis sets. As expected, the inclusion of th e relativistic and correlation effects leads to a decrease of bond lengths and increase of harmonic vibrational frequencies and dissociation energies.