group frequency

https://doi.org/10.1351/goldbook.08609
Frequency in vibrational spectroscopy that is characteristic of a particular chemical functional group.
Note:
The frequency is usually given as a wavenumber.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 748 [Terms] [Paper]