Theoretical molecular packings and the structural model of solid-phase polymerization of fullerene C-60 under high pressures

The set of the optimum packings of C-60 molecules obtained earlier as a res ult of the global search for the potential-energy minima has been analyzed and compared with the structure models of three crystalline phases formed i n the solid-phase polymerization of C-60 under high pressures-orthorhombic (O, formed by linear chains), tetragonal (T, formed by planar tetragonal la yers), and rhombohedral (R, formed by hexagonal layers). It has been reveal ed that four of the calculated packings are characterized by the parallel a rrangement of double bonds of the closest intermolecular contacts, thus pro viding polymerization. Two of these packings have configurations close to t hat of the O phase, one has the configuration close to that of the T phase, and one has the configuration close to the configuration of the R phase. T he optimization of the molecular packings indicates the close relation betw een the corresponding molecular and polymer structures. These data were use d to develop the polymerization mechanism in which the above indicated pack ings play the roles of molecular phases-precursors.