where the underlines represent the species in the resin phase, L represents the ligand species (where Lg = glycolate, Lm = malate and Lc = citrate) and HNd and LNd represent the heavy and the light neodymium isotopes, respectively. In fact, the chemistry of the system may be more complicated than that represented by the above equations. The exact complex structure and the different possibilities of Nd and/or H2O hydrolysis are out of the scope of the present work.
The single stage separation factor, α = (1 + ɛ) for each Nd isotopes is defined here as: