Clinton equations 1 Journal Article 1 N-representability 1 Research Support, Non-U.S. Gov't 1 Research Support, U.S. Gov't, Non-P.H.S. 1 X-ray diffraction 1 density matrix 1 mehr ... electron density 1 idempotent density matrix 1 kernel energy method 1 projector density matrix 1 quantum crystallography 1 quantum theory of atoms in molecules 1 weniger ...