Lorentz unit

Lorentz unit

[′lȯr‚ens ‚yü·nət]
(spectroscopy)
A unit of reciprocal length used to measure the difference, in wave numbers, between a (zero field) spectrum line and its Zeeman components; equal to eH /4π mc 2, where H is the magnetic field strength, c is the speed of light, and e and m are the charge and mass of the electron respectively (gaussian units).