Fig. 1. The schematic model of a Single-Ion Magnet building block (central red sphere) that is coupled to an intra-atomic nuclear spin through the hyperfine interactions (purple), to a radical-bridged spin centre through the direct exchange (green), to a nearby metal ion through a metal–metal bond (red), to a ligand-bridged spin centre through superexchange (yellow), to the dipolar field generated by a distant spin centre (pink), and to the lattice vibration/phonon (the blue ocean).