DENSITY-FUNCTIONAL PARTITIONS

The performance of the local spin density approximation (LSD) of Kohn- Sham density functional theory when applied to partitioned electron de nsities has been explored. Spin partitioning and core/valence partitio ning have each been examined and the results compared with conventiona l Moller-Plesset (MP2) theory based on the Kohn-Sham determinant. It i s found that the LSD energy contributions from such subsets of electro ns are generally in poor agreement with their conventional counterpart s, and it is proposed that such differences be employed as a diagnosti c measure of the quality of other density functionals.