Term: oscillator strength, \(f_{ij}\)
https://doi.org/10.1351/goldbook.O04339

Definition:
Measure for integrated intensity of electronic transitions and related to the Einstein transition probability coefficient Ai j by: \[f_{ij} = 1.4992\times 10^{-14}\ \frac{A_{ij}}{s^{-1}}\ (\frac{\lambda }{\text{nm}})^{2}\] where λ is the transition wavelength. There are, however, differing uses of f.

Related Terms:
1) einstein (http://doi.org/10.1351/goldbook.E01914).
2) probability (http://doi.org/10.1351/goldbook.P04855).
3) coefficient (http://doi.org/10.1351/goldbook.C01124).
4) wavelength (http://doi.org/10.1351/goldbook.W06659).

Source: Green Book, 2nd ed., p. 33 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)

Citation: 'oscillator strength, \(f_{ij}\)' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.O04339

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