34 3j,6j,9j Symbols34.2 Definition: 3j Symbol

§34.1 Special Notation

(For other notation see Notation for the Special Functions.)

2j_{{1}},2j_{{2}},2j_{{3}},2l_{1},2l_{2},2l_{3} nonnegative integers.
r,s,t nonnegative integers.

The main functions treated in this chapter are the Wigner 3j,6j,9j symbols, respectively,

\begin{pmatrix}j_{1}&j_{2}&j_{3}\\
m_{1}&m_{2}&m_{3}\end{pmatrix},
\begin{Bmatrix}j_{1}&j_{2}&j_{3}\\
l_{1}&l_{2}&l_{3}\end{Bmatrix},
\begin{Bmatrix}j_{{11}}&j_{{12}}&j_{{13}}\\
j_{{21}}&j_{{22}}&j_{{23}}\\
j_{{31}}&j_{{32}}&j_{{33}}\end{Bmatrix}.

The most commonly used alternative notation for the 3j symbol is the Clebsch–Gordan coefficient

\left(j_{{1}}m_{{1}}j_{{2}}m_{{2}}|j_{{1}}j_{{2}}j_{{3}}-m_{{3}}\right)=(-1)^{{j_{{1}}-j_{{2}}-m_{{3}}}}(2j_{3}+1)^{{\frac{1}{2}}}\begin{pmatrix}j_{1}&j_{2}&j_{3}\\
m_{1}&m_{2}&m_{3}\end{pmatrix};

see Condon and Shortley (1935). For other notations see Edmonds (1974, pp. 52, 97, 104–105) and Varshalovich et al. (1988, §§8.11, 9.10, 10.10).