New metallic crystalline carbon:: Three dimensionally polymerized C60 fullerite

We explore new polymerized C-60 fullerite phases by using the total-energy calculations in the density-functional theory. Starting from the two dimensionally polymerized tetragonal phase, we find a new stable three dimensionally polymerized structure to be synthesized under uniaxial pressure of about 20 GPa. In sharp contrast to other polymerized C-60 phases and to solid C-60, the new polymer possesses metallic electronic structure with a relatively large Fermi-level density of states. Its conduction-electron distribution and the energetics are studied in detail.