Definition: The molar (decadic) absorption coefficient (formerly: molar decadic extinction coefficient) is an intrinsic property of a given molecule (chromophore) or substance that describes how strongly that molecule/substance absorbs light at a particular wavelength. It is equal to absorbance (A, base 10) divided by the absorption pathlength, d, and the amount concentration, c:
It is generally represented by the unit
cm
L mol
cm
.
Alternative definition:
Synonym: molar absorption coefficient, molar attenuation coefficient
References: https://doi.org/10.1351/goldbook
https://doi.org/10.1351/goldbook.M03972
Related terms: optical density, modified beer-lambert law, attenuation, absorption of light
