Towards an incremental expansion of strong correlation effects in solids



A scheme based on local correlation-energy increments, which has been applied successfully to the investigation of dynamical correlation effects in semiconductors and ionic crystals, is extended here to include non-dynamical (static) electron correlation as well. It is shown how to use abinitio multi-configuration self-consistent-field and multi-reference configuration-interaction calculations for this purpose, and test applications are reported for potential curves of molecules at the dissociation limit.