When calculated with CAM-B3LYP the delocalization in 16 decreases to 15%, although the molecule keeps its tetrahedral structure. We checked the possible multiconfigurational character of these tetrahedral and cubic systems by computing the T1 diagnostic values for 14 and 15 at CCSD(T)/6-311G(d,p)//B3LYP/6-311G(d,p) level. The values obtained were below 0.02 which is the threshold for single-configurational character of closed-shell species, justifying our use of single-reference methods. Interestingly, for the cubes C8(C4)12 (17) and C8(C6)12 (18) the extent of delocalization of the radial -electrons are higher at 43% and 42%, respectively. Based on the CC bond lengths within the hexatriyne segments of 18 (1.229 -1.330 Å) as compared to those of 1,3,5-hexatriyne (1.209 -1.356 Å), it is furthermore clear that there is some degree of bond length equalization in 18 indicative of enhanced bond delocalization which may suggest aromaticity. Zintl ions such as Si4 4-and white phosphorous P4 have earlier been concluded to be 3D-aromatic based on NICS(0) values computed in the tetrahedron centers. Yet, as the electron delocalization decreases with shorter tethers, it should be the lowest in the E4 4-species.