In previous work on clusters, the focus was mainly on the intriguing areas such as boranes, metalloboranes, metal carbonyls, zintl ions, matryoshka clusters, and golden clusters. This resulted into the discovery of the skeletal numbers, double-capping theory, clusters with nuclear centers and the concomitant nuclear zone and the cluster valence electron equations and the linkage between the cluster number and the corresponding isomeric structures. In this work, the focus is mainly on the main group clusters ranging from the nuclearity index n=1 to32. These clusters include diatomic species involving, B, C, N, and O. The coverage is extended to cover some selected compounds of Si, P and Cl as well as the oxo-acids.In this study, the energy level concept of cluster valence electrons based on s2, p6 and d10 relationship was emphasized. This relationship assigned the [H] element to be at the lowest level, while the main group elements were assigned the middle slot while the transition metals were assigned the top level.