Characteristic quantity used in the analysis of absolute infrared intensity data chosen on the assumption that the electric dipole moment of the molecule can be described as the vector sum of bond dipole moments.
Notes: - The original EOPs were \(\mu_{k}^{\circ}\), the equilibrium bond moment, and \(\partial \mu_{k}/\partial R_{t}\), the change in the electric dipole moment of bond \(k\) with change in internal displacement coordinate \(t\). A later and completely equivalent formulation uses equilibrium atomic charges, \(q_{\alpha}^{\rm{o}}\), and charge fluxes, \(\partial q_{\alpha}/\partial R_{t}\), which are also called EOPs as well as ECCF for equilibrium charge, charge flux.
- In Note 1, \(R\), are vibrational coordinates such as bond stretching, angle deformation, or torsion about a bond.
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 745 (https://doi.org/10.1515/pac-2019-0203)