Wigner-Eckart theorem


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Wigner-Eckart theorem

[′wig·nər ′ek·ərt ‚thir·əm]
(quantum mechanics)
A theorem in the quantum theory of angular momentum which states that the matrix elements of a tensor operator can be factored into two quantities, the first of which is a vector-coupling coefficient, and the second of which contains the information about the physical properties of the particular states and operator, and is completely independent of the magnetic quantum numbers.
References in periodicals archive ?
In this paper, f-f MD transition in rare-earth doped crystals is investigated and general expressions of magnetic permeability are derived according to semi-classic theory and Wigner-Eckart theorem.
The Wigner-Eckart theorem shows that (6) can be cast into a product of a Wigner 3j symbol and a reduced matrix element [10, see p.