The SPME for the Eλ operator is given by ⟨ka||O(Eλ)||kb⟩=(−1)ja+1/2[1+(−1)la+λ+lb]2 ×√(2ja+1)(2λ+1)(2jb+1)4π(jaλjb1/20−1/2)⟨ka|rλ|kb⟩eqe.