Structural classification ofAB2molecules andA3clusters from valence electron orbital radii

Abstract
We show that a priori atomic parameters (valence-orbital radii) allow classifications of molecular shapes for a large number of sp-bonded AB2 compounds with the number of valence electrons N≤16, in parallel with classifications of crystal structures in the solid phase. Triatomic A3 clusters with N≤15 are structurally classified with the same scheme.