First-principles molecular-dynamics simulation is carried out for covalent systems with arbitrary (i.e., tetrahedral and nontetrahedral) coordination in a nonorthogonal, tight-binding basis, generalizing previous successful applications to tetrahedral solids. The generalized method is applied to study various aspects of the ${\mathrm{C}}_{60}$ molecule, including the effect of doping on vibrational modes, and interaction with heteroatoms. Considerable increase in the double-bond length and a much smaller increase in the single-bond length are found. Oxygen chemisorption occurs over the bridge site along the carbon-carbon double bond, weakening the latter.

• Received 8 August 1991

DOI:https://doi.org/10.1103/PhysRevLett.67.3487