Here we present preliminary results on Mg4C60, a new fulleride polymer. A series of MgxC60compositions were prepared by solid state synthesis. While most samples were multiphase, the nominal composition Mg4C60provided a single phase material. X‐ray powder diffraction data revealed that the structure is rhombohedral based on polymeric sheets of C60molecules. Charge transfer from Mg to C60was estimated by Raman microscopy. © 2003 American Institute of Physics