<Ul> <Li> Attenuation coefficient, sometimes called "extinction coefficient" in meteorology or climatology <Ul> <Li> Mass extinction coefficient, how strongly a substance absorbs light at a given wavelength, per mass density </Li> <Li> Molar extinction coefficient, how strongly a substance absorbs light at a given wavelength, per molar concentration </Li> </Ul> </Li> <Li> Imaginary part of the complex index of refraction, in physics </Li> </Ul> <Li> Attenuation coefficient, sometimes called "extinction coefficient" in meteorology or climatology <Ul> <Li> Mass extinction coefficient, how strongly a substance absorbs light at a given wavelength, per mass density </Li> <Li> Molar extinction coefficient, how strongly a substance absorbs light at a given wavelength, per molar concentration </Li> </Ul> </Li> <Ul> <Li> Mass extinction coefficient, how strongly a substance absorbs light at a given wavelength, per mass density </Li> <Li> Molar extinction coefficient, how strongly a substance absorbs light at a given wavelength, per molar concentration </Li> </Ul> <Li> Mass extinction coefficient, how strongly a substance absorbs light at a given wavelength, per mass density </Li>

What are the units for the molar extinction coefficient