▎ 摘　　要

Large basis set local-density-functional calculations on fullerenes, graphene and graphite suggest that fullerene stability increases monotonically with the number of carbon atoms (N), and is nearly linear in 1/N. C-60 is less stable energetically than C-70 and higher fullerenes, despite the apparent preference for C-60 in nature. The heat of formation found here for C-60 relative to graphite is in good agreement with experiment, while the heat of formation for graphene relative to graphite is overestimated by a factor of two.