Electromagnetic multipole moments and transitions

The SPME for the orbital part of the magnetic operator is: $$ \langle k_{a}\vert\vert O(M\lambda ,l )\vert\vert k_{b}\rangle= $$ $$ = \frac{\sqrt{\lambda (2\lambda +1)}\, }{\lambda +1} \langle j_{a}\vert\vert [Y^{\lambda -1}(\hat{r})\otimes\mathbf{l}\,]^{\lambda }\vert\vert j_{b}\rangle \langle k_{a}\vert r^{\lambda -1}\vert k_{b}\rangle g^{l }_{q}\mu _{N} $$ $$ =\frac{\sqrt{\lambda (2\lambda +1)}\, }{\lambda +1}(-1)^{l _{a}+1/2+j_{b}+\lambda } \sqrt{(2j_{a}+1)(2j_{b}+1)} $$ $$ \times\left\{\begin{array}{ccc} {l _{a}} & {l _{b}} & {\lambda} \\ {j_{b}}& {j_{a}}& {1/2}\end{array}\right\} \langle l _{a}\vert\vert [Y^{\lambda -1}(\hat{r})\otimes\mathbf{l}\,]^{\lambda }\vert\vert l _{b}\rangle \langle k_{a}\vert r^{\lambda -1}\vert k_{b}\rangle g^{l }_{q}\mu _{N}, $$