On formation of polyatomic mercury cations

This paper analyzes the effect of the increased number of electrons lying on the 6s orbitals of Hg ions on the formation of polyatomic Hgn cations, their structure, and Hg-Hg distances. The critical role in the formation and structural characterstics of Hgn cations is played by the degree of expansion of the Hg5d atomic orbitals; when 6s electrons increase in number, this expansion is enhanced by relativistic effects. Formation of Hgn cations and the observed tendencies are explained in terms of the virial theorem.