Ab initio relativistic effective potential and relativistic configuration interaction calculations on diatomic molecules containing heavy elements

Ab initio relativistic effective potential and relativistic CI techniques have been used to perform calculations on the hydrides, oxides, fluorides and chlorides of scandium, lutetium and lawrencium.

In order to establish the validity of the method, the results on the hydrides, oxides, fluorides and chlorides are compared with previous calculations both at the SCF and CI levels. The calculated spectroscopic properties (R_e, D_e and ω_e) are also compared with the available experimental results. In general, they are in good agreement.

The wavefunctions produced are used to interpret the bonding in the twelve molecules investigated with particular emphasis on the effects of the relativistic terms included in the Hamiltonian. The results show that the bonding and spectroscopic constants for the lawrencium compounds are surprisingly similar to those values found for lutetium.