An infinite square lattice of super-supertetrahedral T6-like tin oxyselenide clusters

Abstract
A new super-supertetrahedral cluster, resembling a coreless supertetrahedral T6 cluster, was made as a tin oxyselenide by integrating hard and soft Lewis bases (O2− and Se2−) into the tetravalent system. Its hierarchical architecture, built from supertetrahedral T3-[Sn10O4Se20] and Sn2Se6 clusters, represents a new level of complexity in the cluster-based construction. Compared to pure tin selenides, the new tin oxyselenide material in this work shows much enhanced stability and size-dependent band energy level.