fine structure

[ fahyn ]
/ faɪn /

noun Physics.

a group of lines that are observed in the spectra of certain elements, as hydrogen, and that are caused by various couplings of the azimuthal quantum number and the angular momentum quantum number.

Origin of fine structure

First recorded in 1915–20

British Dictionary definitions for fine structure

fine structure

noun

the splitting of a spectral line into two or more closely spaced components as a result of interaction between the spin and orbital angular momenta of the atomic electrons Compare hyperfine structure