symbol: $\alpha$
synonyms: absorption coefficient, Napierian absorption coefficient
https://doi.org/10.1351/goldbook.08265
Napierian absorbance (\(A_{\rm{e}}\)) divided by path-length (\(l\)). \(\alpha = A_{\rm{e}}/l\).
Note: \(\alpha\) is the reciprocal of the optical absorption depth.