To summarize, the fast convergence of LASSI [1,q] with respect to q in the (11,10) active space displayed in Fig. is fortuitous and artifactual: one of the orbitals has an arbitrary shape, which happens to effectively exclude its involvement from the LASSI[1,q] model space. In the more reasonable (11,20) active space, in which all orbitals have well-defined shapes, convergence with respect to q is poor, because the energetically-preferred electron hopping out of the doubly-occupied orbital does not meaningfully contribute to the physical phenomenon of kinetic exchange, which requires that the electrons in the singly-occupied orbitals of the two fragments pair up.