Investigations of the CASE approximation using the optimal partition of the Coulomb operator

A number of recently developed techniques for the computation of the Coulomb energy in O(N) work derive from the partitioning of 1/r into short- and long-range components. Considering only the short-range component of this operator yields the Coulomb-attenuated Schrِdinger equation (CASE). We examine the chemistry resulting from the combination of the CASE approximation with the optimal partition of the Coulomb operator.