1. The problem statement, all variables and given/known data 2. Relevant equations https://en.wikipedia.org/wiki/Clebsch–Gordan_coefficients I don't know how to calculate tensors though.. 3. The attempt at a solution OK so how do I even proceed? All I know about Clebsch-Gordon coefficients is that you can use them to calculate total spin of two spinors, and allegedly the total angular momentum too. My knowledge is basically limited to level of Griffith's intro to QM. Help?