Multibody analysis of potential energy surfaces for first‐ and second‐row tetramers. II. The cases of O 4 and S 4

Calculations on different geometries of O 3 , S 3 , O 4 , and S 4 clusters show that oxygen and sulfur present quite different behavior as concerns cluster formation. O 3 has a C 2v , symmetry while S 3 is equilateral D 3h . O 4 cannot form a structure with near‐equal bond lengths while S 3 can form several such structures, of which the ring structures are more stable than the chain or branched structures. A multibody analysis of the cluster energies gives a cogent rationale of these differences, showing for instance that large three‐body nonadditive repulsions make O 4 unstable, while three‐body effects turn out to be attractive for S 4 .