emerged from DFT? (2.5.1) Gill : Inspection of the electronic Schrödinger equation for a large molecule does not lead one to anticipate that most of its interesting properties can be partitioned into almostadditive contributions from its various parts. As a result, there is an apparent inconsistency between the baroque complexity of quantum chemistry's many-body framework and the simplicity and predictive power of chemistry's "functional group" paradigm. Kohn-Sham DFT models, in which the exchange-correlation energy is approximated by an integral over all space of a function of the electron density, have partially bridged that conceptual gap.