The same commutation relations apply for the other angular momentum operators (spin and total angular momentum): [ S l , S m ] = i ℏ ℏ ∑ ∑ n = 1 3 ε ε l m n S n , [ J l , J m ] = i ℏ ℏ ∑ ∑ n = 1 3 ε ε l m n J n .