Clarification of Some Bonding Concepts: Virial Theorem, Electron Pair Repulsion, and Rotational Barriers
Year: 2025
Type: article
Abstract: The molecular virial theorem relates kinetic and potential energies (T & V) to total energy and forces (E & R·∂E/∂R); it is a useful tool for analyzing the data, but does not provide clues on the origin of the stability of the "bonded" state. A strict conceptual distinction between cause and effect is recommended. Depending on the physical relationships, the induced change of one variable of the system leads to a resulting change of another variable; relaxation or response of the system can either moderate this change (in the sense of Le Chatelier's principle), enhance it, or even reverse it. Such unexpected, paradoxical behavior is common in reality and in daily life. As two examples of conceptual mix-up in molecular chemistry, we discuss details of the origin of the steric pair-pair repulsion and of the internal rotation barrier in ethane.
DOI: 10.1002/jcc.70085
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,520
OpenAlex ID: W4408956419