A refined version of the ‘‘shape consistent’’ effective potential procedure of Christiansen, Lee, and Pitzer was used to compute averaged relativistic effective potentials (AREP) and spin–orbit operators for the elements Rb through Xe. Particular attention was given to the partitioning of the core and valence space and, where appropriate, more than one set of potentials is provided. These are tabulated in analytic form. Gaussian basis sets with contraction coefficients for the lowest energy state of each atom are given. The reliability of the transition metal AREPs was examined by comparing computed atomic excitation energies with accurate all-electron relativistic values. The spin–orbit operators were tested in calculations on selected atoms.

A b initio averaged relativistic effective core potentials (AREP) and spin–orbit (SO) operators are reported for the elements Cs through Rn. Two sets have been calculated for certain elements to provide AREPs with varying core/valence space definitions thereby permitting the treatment of core–valence correlation interactions. The AREPs and SO operators are tabulated as expansions in Gaussian-type functions (GTF). GTF valence basis sets for the lowest energy state of each atom are tabulated. The reliability of the AREPs and SO operators is gauged by comparing calculated atomic excitation energies and SO splitting energies with all-electron relativistic values. Calculated atomic excitation energies are found to agree to 0.12 eV and SO energies to 3.4%.

A refined version of the ‘‘shape consistent’’ effective potential procedure of Christiansen, Lee, and Pitzer was used to compute averaged relativistic effective potentials (AREP) and spin-orbit operators for the atoms K through Kr. Particular attention was given to the partitioning of the core and valence space, and where appropriate more than one set of potentials is provided. These are tabulated in analytic form. Gaussian basis sets with expansion coefficients for the lowest energy state of each atom are given. The reliability of the transition metal AREPs was determined by comparing computed atomic excitation energies with accurate all-electron relativistic values. In all cases the maximum error was found to be less than 0.1 eV. The reliability of the spin-orbit operators was also considered.

Ab initio averaged relativistic effective core potentials (AREP), spin-orbit (so) operators, and valence basis sets are reported for the elements Fr through Pu in the form of expansions in Gaussian-type functions. Gaussian basis sets with expansion coefficients for the low-energy states of each atom are given. Atomic orbital energies calculated under the j -j coupling scheme within the self-consistent field approximation and employing the AREP'S in their unaveraged form (REP'S) agree to within 10% of orbital energies due to numerical all-electron Dirac-Fock calculations. The accuracy of the AREP'S and so operators is also shown to be good through comparisons of calculated so splitting energies with all-electron Dirac-Fock results.

Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and