reaction barrier

https://doi.org/10.1351/goldbook.R05166
The energy barrier to chemical reaction. In vibrationally
adiabatic transition-state theory
its height is the zero-point energy of the
activated complex
minus that of the reactants.
Source:
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 183 [Terms] [Paper]