wavenumber in vacuum symbol: ν~, units: m1, cm1

Synonym: vacuum wavenumber
https://doi.org/10.1351/goldbook.08302
Reciprocal of the vacuum wavelength of electromagnetic radiation. ν~=1/λ0.
Notes:
  1. Wavenumber is related to the energy change, ΔE, induced when the radiation is absorbed by ΔE=hc0ν~, where h is the Planck constant and c0 the speed of the radiation.
  2. Wavenumber should only be used when no confusion with frequency is possible.
  3. The symbol ν is often used instead of ν~; this usage should be discouraged.
  4. SI unit: m1. Common unit: cm1.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 678 [Terms] [Paper]