Note that [ Ûθ , Ûµ ] = 0 since they act on different degrees of freedom. In this way, ĤPFS and Ĥp•A are intrinsically related. It follows naturally that they would have very similar convergence properties. Consequentially, in the full basis limit, the PFS representation is equivalent to the p•A Hamiltonian. This is shown in the following section.