strain energy
The excess energy due to @[email protected] of a molecular entity or @[email protected] structure, i.e. distortions relative to a reference (real or hypothetical) 'strainless' structure with the standard bond lengths, bond angles and dihedral angles. The @[email protected] energy components involve the following destabilizing terms: non-bonded repulsions, [email protected]@ distortions, bond stretch or compression, rotation around or twisting of double bonds, and electrostatic @[email protected] In general, the contributions of these components are inseparable and interdependent. A quantitative assessment of @[email protected] and @[email protected] energies can be made by taking the difference between the heat of formation of the substance under consideration and that of a hypothetical @[email protected] model. Several approaches to the assessment of @[email protected] energies have been developed based on the use of energies of isodesmic and homodesmotic reactions and on the so-called 'strainless increments', i.e. heats of formation of certain groups (CH3, CH2, CH, C etc).
PAC, 1999, 71, 1919. (Glossary of terms used in theoretical organic chemistry) on page 1964 [Terms] [Paper]