Wigner-Eckart theorem


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.