Cs₃C₆₀ formed from C₆₀ and cesium

Superconducting Cs₃C₆₀  has the highest T_c of any molecular material at 38 K. The superconducting phase structure is based on body-centred-cubic packing. It is an example of a molecular material.

Potassium forms similar face centred cubic structures.

Bulk Superconductivity at 38 K in a Molecular System, Ganin, A. Y.; Takabayashi, Y.; Khimyak, Y. Z.; Margadonna, S.; Tamai, A.; Rosseinsky, M. J.; Prassides, K.  Nature Materials, 7, 367–371 (2008)

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