An Etymological Dictionary of Astronomy and Astrophysics

The constant of proportionality relating the separations of lines of successive pairs of adjacent components of the levels of a spectral multiplet to the larger of the two J-values for the respective pairs. The interval between two successive components J and J + 1 is proportional to J + 1.

See also: After Alfred Landé (1888-1976), a German-American physicist, known for his contributions to quantum theory; → facteur.