## Wikipedia - قوة تذبذب (ar) oscillator strength, $$f_{ij}$$

https://doi.org/10.1351/goldbook.O04339
Measure for integrated intensity of electronic transitions and related to the @[email protected] transition @[email protected] @[email protected] $$A_{ij}$$ by: $f_{ij} = 1.4992\times 10^{-14}\ \frac{A_{ij}}{s^{-1}}\ (\frac{\lambda }{\text{nm}})^{2}$ where $$\lambda$$ is the transition @[email protected] There are, however, differing uses of $$f$$.
Source:
Green Book, 2nd ed., p. 33 [Terms] [Book]
See also:
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2257 [Terms] [Paper]