Ab Initio Study of Structural, Electronic, and Magnetic Properties of Vn(C60)m Complexes

We have studied structural, electronic, and magnetic properties of transition-metal-fullerene complexes V-n(C-60)(m), (n, m) = (1, 1), (1, 2), (2, 3), (3, 4), (4, 4) by means of a density functional theory method. We have examined relative stabilities of complexes with different V-C-60 binding sites (V atoms are bound to either pentagonal or hexagonal rings of C-60) and with different stacking configurations (linear or nonlinear). The linearly stacked sandwichlike complexes with V atoms binding to hexagonal rings of C-60 are the most stable for (n, m) = (n, n + 1), although nonlinearly stacked configurations call be energetically competitive. For (n, m) = (1, 1), the V atom tends to bind to a pentagonal ring of the C-60 molecule. For (n, m) = (4, 4), a riceball-like structure is found to be the most stable. Except for (n, m) = (1, 1), the lowest-energy structures of the complexes are generally in their lowest spin states.