Reaction coordinate
A reaction coordinate is in the Chemistry a one-dimensional coordinate that as a geometric parameter the progress of a chemical elementary reaction along the reaction path (the trajectory) on the potential energy surface describes the atoms involved in the reaction. The reaction coordinate can be used as a generalized coordinate to describe the geometry of a system of n atoms in the course of a reaction; in addition to the reaction coordinate 3 n −7, further generalized coordinates are required.
In molecular dynamics simulations, reaction coordinates that describe the folding state of a protein are called collective variables .
Reaction coordinates can sometimes be represented in a simple way in spatial space ( bond length , bond angle , ...). However, this is difficult for more complex reaction coordinates, especially if non-geometric parameters such as the bond order are used.
In energy diagrams, the Gibbs energy is plotted as a function of the reaction coordinate in order to demonstrate the energy profiles that are passed through in the course of a chemical reaction.
Individual evidence
- ↑ Entry on Reaction coordinate . In: IUPAC Compendium of Chemical Terminology (the “Gold Book”) . doi : 10.1351 / goldbook.R05168 .
- ^ Mark E. Tuckerman: Reaction coordinates