zero-point energy

https://doi.org/10.1351/goldbook.08215
Extent, in consequence of Heisenberg’s Uncertainty Principle, by which a particle or a set of particles has an energy greater than that of the minimum on the potential-energy surface.
Notes:
  1. Because of zero-point energy, a molecular entity has a nonzero probability of adopting a geometry whose energy is greater than that of the energy minimum.
  2. A molecular entity with zero-point energy may even adopt a geometry with a potential energy greater than its total energy, a possibility that permits tunnelling.
  3. Because the magnitude of zero-point energy increases with decreasing mass, it is significant in the context of isotope effects, especially of hydrogen isotopes.
Source:
PAC, 2022, 94, 353. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)) on page 525 [Terms] [Paper]