Tohoku University researchers have observed a rare change in the structure of a mineral-like crystal that, if controlled, could lead to the development of new functional materials. The findings were reported in the Journal of the American Chemical Society (“Cation Dimerization in a 3d1 honeycomb lattice system”). The crystal structure of ilmenite-type magnesium vanadate (MgVO3). The yellow line shows the honeycomb lattice. The thick lines indicate the location of V-V dimers. The crystal structure was drawn using VESTA-3 software. Altering the atomic arrangements within materials can change their magnetic, electrical and optical properties. For instance, the pairing of positively charged cations in quasi one-dimensional crystals, such as vanadium dioxide (VO2), creates ‘covalent’ bonds, which can change the material’s electronic state and thus its conductivity.