Scientists have synthesized sub-nanometer particles with precisely controlled proportions of indium and tin using specific macromolecular templates called dendrimers. Through a screening process spanning different metallic ratios, they discovered unusual electronic states and optical properties originating from size-miniaturization and elemental-hybridization. Their approach could be a first step in the development of sub-nanoparticles with unique functionalities and characteristics for electronic, magnetic, and catalytic applications.