NEW RELATIVISTIC EFFECTIVE CORE POTENTIALS FOR HEAVY-ELEMENTS

A relativistic ECP based on the AIMP method and with explicit relativi stic no-pair operators included in the Hamiltonian is described. Calcu lated excitation energies of the third row transition metals and spect roscopic constants for the third row transition metal hydrides are pre sented. The results are compared with relativistic all-electron no-pai r results. The agreement between the all-electron and the ECP results is very good.