symbol: $\tilde{\nu}$, units: $\pu{m-1}$, $\pu{cm-1}$
synonym: vacuum wavenumber
https://doi.org/10.1351/goldbook.08302
Reciprocal of the vacuum wavelength of electromagnetic radiation. \(\tilde{\nu} = 1/\lambda_{0}\).
Notes:
- Wavenumber is related to the energy change, \(\Delta E\), induced when the radiation is absorbed by \(\Delta E = hc_{0}\tilde{\nu}\), where \(h\) is the Planck constant and \(c_{0}\) the speed of the radiation.
- Wavenumber should only be used when no confusion with frequency is possible.
- The symbol \(\nu\) is often used instead of \(\tilde{\nu}\); this usage should be discouraged.
- SI unit: \(\pu{m-1}\). Common unit: \(\pu{cm-1}\).