The crystal structure of the 2D polymerized tetragonal phase of <f>C60</f>

Single crystals of the 2D polymerized tetragonal phase of <f>C60</f> without orientational domains were obtained under high pressure and high temperature. The crystal structure of this phase was resolved using single crystal X-ray diffraction data. The cell parameters are <f>a=9.064(3)</f> and <f>c=15.039(8)</f> A˚ with the space group <f>P42/mmc</f> and <f>Z=2</f>. A structural model of this phase proposed early was confirmed and refined to final <f>R=0.075</f>. The structure is slightly disordered. It consists of a random combination of the <f>P42/mmc</f> layers (84%) and of the Immm layers (16%), along the c-axis. [Copyright &y& Elsevier]