frequency, \(\nu\), \(\omega\)

in photochemistry
https://doi.org/10.1351/goldbook.FT07383
The number of waveperiods per time interval. The linear frequency, ν, is the number of cycles per time interval. SI unit Hz = s-1.
Note:
For the @A00352@ the symbol \(\omega\) (\(= 2\pi\nu\)) is used with \(\text{rad s}^{-1}\) as the SI unit.
See also: frequency
Source:
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 345 (https://doi.org/10.1351/pac200779030293)