This week I’ve been reviewing the properties of the Wigner nj symbols.

**3j-Symbols**

Relation to Clebsh-Gordan coefficients:

Compatibility criteria

vanishes if the following are not true:

Symmetries

**6j-Symbols**

Definition in terms of 3j’s

Symmetries

Compatibility

,

unless the triangle inequalities hold for {a,b;,c}; {a,e;,f}, {d,b,f}and {d,e,c}

Orthogonality

**9j-Symbols**

Definition by 3j’s

Definition by 6j’s

Symmetries

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