FIRST APPEARANCE OF THE "LANDÉ INTERVAL RULE"

LANDÉ, A.

Termstruktur und Zeemaneffekt der Multipletts.

(Braunschweig, Berlin, Vieweg & Sohn u. Julius Springer, 1923) 8vo. As extracted from "Zeitschrift für Physik", Bd. 15. (Entire volume offered). A stamp on front free end paper.. Pp.189-205. [Entire volume: IV,420 pp].

First appearance of Lalandé's important paper, in which the "Lalandé interval rule" was introduced for the very first time.
"Lalandé interval rule states that when the spin-orbit interaction is weak enough to be treated as a perturbation, an energy level having definite spin angular momentum and orbital angular momentum is split into levels of differing total angular momentum, so that the interval between successive levels is proportional to the larger of their total angular momentum values.

Order-nr.: 48984