Vertical ionisation energy is the energy required to remove an electron from an atom, molecule, or ion in the gas phase without moving any nuclei. The vertical ionisation energy is greater than or equal to the adiabatic ionisation energy.
Generalic, Eni. "Vertical ionisation energy." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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