I mailed the reprint of my paper with Prof. Cuccia, "Molecular Modeling of Fullerenes with Beads" (J. Chem. Edu 2012 , 89 (3), 414–416) to Prof. Henry Bent two months ago. He is the person who proposed the tangent sphere model in the 60s. He made the following comments on the beaded molecules:
"... contributions to the literature on molecular modeling such sophisticated molecules with so elegantly simple methods: beads and string, that's all!"
"The saturation and directional character of chemical affinity falls out naturally from your bead models without any need to refer, e.g., to Schrödinger's equation and atomic orbitals when constructing approximate electron density profiles, even for molecules as complicated as the fullerenes."