Harmonic constant

{
  "id": "MLC-T-CHM-005108",
  "term": "Harmonic constant",
  "field": "Chemistry",
  "definition": "The harmonic vibrational wavenumber of a molecule, symbol ωe, which multiplies the quantum number term (v + 1/2) in the expression for vibrational term values and is fixed by the quadratic part of the potential energy curve. For a diatomic molecule ωe = (1/2πc)√(k/μ), with k the force constant and μ the reduced mass, and it is usually reported in cm⁻¹. Carbon monoxide has an ωe of about 2170 cm⁻¹.",
  "synonyms": [
    "harmonic wavenumber"
  ],
  "subject": "Analytical Chemistry",
  "see_also": [
    "vibrational potential energy",
    "vibrational term value"
  ],
  "references": [
    "PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 748 (https://doi.org/10.1515/pac-2019-0203)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/harmonic-constant/"
}