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 \(f\).