The difference between the total energy of a molecular system and the sum of the energies of its isolated π- and σ-bonds. The value of binding energy depends upon the geometrical arrangement of the isolated subunits (molecules). According to another definition, the term to be subtracted from the total energy is the sum of the energies of the separate atoms in the corresponding valence
states, which compose the molecule.
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook