Alfred Landé (13.12.1888-1975) was a German theoretical physicist. He was born in Elberfeld. He studied at the universities of Munich and Göttingen. In 1920—22 he worked at the University of Frankfurt, and in 1922 — 31 he was professor at the University of Tübingen. From 1931 he was professor at Ohio State University (USA).
His research was in the field of the study of atomic structure (models of the helium and carbon atoms), atomic spectra and the Zeeman effect, multiplet theory, quantum theory, thermodynamics and quantum mechanics. In 1918 he proposed a cubic model of the atom, and in 1919 he extended the model of the alkali atom, describing the motion of the electron by three quantum numbers (the vector model). From the observed splitting of spectral lines he derived the simpler splitting of spectral terms, and he applied half-integer values of the magnetic quantum numbers to the doublet spectra of the alkali metals. He was the first to calculate the terms in the case of the anomalous Zeeman effect, he found the value of the inner quantum number, and in 1922 he introduced
the g-factor (the Landé factor).