The most commonly employed sp basis is the harmonic oscillator, which in turn means that a two-particle wave function with total angular momentum \( J \) and isospin \( T \) can be expressed as $$ \begin{array}{ll} \vert (n_{a}l_{a}j_{a})(n_{b}l_{b}j_{b})JT\rangle =& {\displaystyle \frac{1}{\sqrt{(1+\delta_{12})}} \sum_{\lambda S{\cal J}}\sum_{nNlL}} F\times \langle ab|\lambda SJ \rangle\\ &\times (-1)^{\lambda +{\cal J}-L-S}\hat{\lambda} \left\{\begin{array}{ccc}L&l&\lambda\\S&J&{\cal J} \end{array}\right\}\\ &\times \left\langle nlNL| n_al_an_bl_b\right\rangle \vert nlNL{\cal J}ST\rangle ,\end{array} \tag{4} $$ where the term \( \left\langle nlNL| n_al_an_bl_b\right\rangle \) is the so-called Moshinsky-Talmi transformation coefficient (see chapter 18 of Alex Brown's notes).