The fifth chapter describes the bonding interaction in chemically synthesized superatomic molecules [M1Au37(PET)24]− (PET = 2-PhC2H4S; M = Pd, Pt). Au38(PET)24 is known to have a bi-icosahedral Au23 core consisting of two Au13 icosahedrons by sharing three Au atoms. Previous theoretical studies based on a super valence bond (SVB) model have demonstrated that the bonding scheme in the Au23 core is similar to that in the F2 molecule. The SVB model predicted that the electron configuration of the Au23 core with 14 valence electrons is expressed as (1Σ)2(1Σ*)2(1Π)4(2Σ)2(1Π*)4 where each orbital is created by the bonding and antibonding interactions between the 1S and 1P superatomic orbitals of the icosahedral Au13 units. Therefore, the bi-icosahedral Au23 can be viewed as a di-superatomic molecule. To validate the SVB model, I conducted anion photoelectron spectroscopy (PES) on [M1Au37(PET)24]− (M = Pd and Pt), which are isoelectronic and isostructural with Au38(PET)24. I conducted density functional theory calculations to confirm the isoelectronicity of [M1Au37(PET)24]− and Au38(PET)24. Anion PES on [M1Au37(PET)24]− observed two distinctive peaks as predicted by the SVB model: one from the nearly degenerate 1Π* orbitals and the other from the nearly degenerated 1Π and 2Σ orbitals, providing the experimental support of the SVB model.