Recent Progress in Atomic and Chemical Group Effective Potentials

Recent progress on atomic and chemical group effective potentials is presented. The reviewed effective potentials follow a shape-consistent extraction technique from ab initio data, within a scalar relativistic approximation. Two types of averaged relativistic effective core potentials are considered:  the correlated ones where a part of the correlation energy is included in the effective potential, and the polarized ones for which only the core polarization effects are taken into account. In addition spin−orbit polarized pseudopotentials have been extracted, and the effects of the core polarization are tested on the atomic spectroscopy of iodine. Finally a very recent chemical group effective methodology is presented, reducing the number of both electrons and nuclei explicitly treated. Chemical transferability is investigated, and test calculations on a cyclopentadienyl effective group potential are presented.