Vertical ionization

{
  "id": "MLC-T-CHM-012553",
  "term": "Vertical ionization",
  "field": "Chemistry",
  "definition": "An ionization process where the geometry of the molecule remains unchanged during the removal of an electron. This implies that the nuclear positions in the resulting ion are the same as in the neutral molecule at the instant of ionization. The energy required for this process is known as the vertical ionization energy, which corresponds to a transition from the ground vibrational state of the neutral molecule to a specific vibrational state of the ion.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "excited state"
  ],
  "references": [
    "PAC, 1991, 63, 1541. 'Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)' on page 1548 (https://doi.org/10.1351/pac199163101541)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/vertical-ionization/"
}