ABSTRACT:We describe quantitative numerical applications of the natural Ž . resonance theory NRT to a variety of chemical bonding types, in order to demonstrate the generality and practicality of the method for a wide range of . chemical systems. Illustrative applications are presented for 1 benzene and . . polycyclic aromatics; 2 CO , formate, and related acyclic species; 3 ionic and 2 .. polar compounds; 4 coordinate covalent compounds and complexes; 5 . hypervalent and electron-deficient species; 6 noncovalent H-bonded complex;. and 7 a model Diels-Alder chemical reaction surface. The examples exhibit the general harmony of NRT weightings with qualitative resonance-theoretic concepts and illustrate how these concepts can be extended to many new types of chemical phenomena at a quanitative ab initio level. ᮊ