In LASSI[r,q], 19 model states are sorted into "rootspaces," where one "rootspace" describes a single distribution of electrons among the fragments along with a single choice of spin magnitude quantum numbers for each fragment. Rootspaces are enumerated by, beginning from a single reference LASSCF wave function, moving one electron from any one fragment to any other fragment in all possible ways up to r ≥ 0 times. An example is depicted in Fig. .