Lorentzian band shape

This band shape is described by the function: \[F\left(\nu - \nu _{0}\right) = \frac{1}{\pi }\ \gamma \ ((\nu - \nu _{0})^{2}+\gamma ^{2})^{-1}\] where v 0 is the mean band position, γ is the half band width at half maximum, and F(ν - ν0) is the frequency distribution function.
See also: Gaussian band shape
PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2252 (https://doi.org/10.1351/pac199668122223)