 Reaction coordinate

A reaction coordinate parametrizes changes in molecular configuration along a chemical reaction path. It can involve a bond length, a bond angle, or a combination of geometric changes. It is not elapsed time and is not the bulk extent of reaction: one describes configurations, while the other accounts for how much material has converted. The precise choice matters when interpreting an energy profile. See the IUPAC Gold Book: reaction coordinate.

A reaction coordinate is a concept used in chemistry and physics to describe the progress of a chemical reaction as it proceeds from reactants to products. It is often represented as a one-dimensional plot that captures changes in energy over the course of the reaction. The reaction coordinate typically represents the arrangement of atoms and the potential energy of the system, illustrating how the reactants transition through an intermediate state (if applicable) to form the products.