The term \( \langle ab|LSJ \rangle \) is a shorthand
for the \( LS-jj \) transformation coefficient,
$$
\langle ab|\lambda SJ \rangle = \hat{j_{a}}\hat{j_{b}}
\hat{\lambda}\hat{S}
\left\{
\begin{array}{ccc}
l_{a}&s_a&j_{a}\\
l_{b}&s_b&j_{b}\\
\lambda &S &J
\end{array}
\right\}.
$$
Here
we use \( \hat{x} = \sqrt{2x +1} \).
The factor \( F \) is defined as \( F=\frac{1-(-1)^{l+S+T}}{\sqrt{2}} \) if
\( s_a = s_b \) and we .