isoclinic point

https://doi.org/10.1351/goldbook.I03265
A @W06659@, wavenumber, or frequency at which the first derivative of an @A00043@ of a sample does not change upon a chemical reaction or physical change of the sample.
Source:
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2249 [Terms] [Paper]