The number of 16 states is the hallmark of a fully developed SU(4) symmetry that would be achieved in the 2e-VFCI in the absence of any spin-isospin coupling (i.e., neglecting the H VOC and/or H SIC terms) and for the case of a vanishing valley gap (E V = 0). These sixteen states are the product of the four spin states (one singlet, S s , and three triplets, T s ± and T s 0 ) and the four valley isospin states (one singlet, S v , and three triplets,