Density functional calculations on the geometric structure and properties of the 3d transition metal atom doped endohedral fullerene M@C₂₀F₂₀ (M= Sc--Ni)

This paper uses the generalised gradient approximation based on density functional theory to analyse the geometric structure and properties of the 3d transition metal atom doped endohedral fullerene M@C₂₀F₂₀ (M = Sc--Ni). The geometric optimization shows that the cage centre is the most stable position for M, forming the structure named as M@C₂₀F₂₀-4. The inclusion energy, zero-point energy, and energy gap calculations tell us that Ni@C₂₀F₂₀-4 should be thermodynamically and kinetically stablest. M@C₂₀F₂₀-4 (M = Sc--Co) possesses high magnetic moments varied from 1 to 6 μ_B, while Ni@C₂₀F₂₀-4 is nonmagnetic. The Ni--C bond in Ni@C₂₀F₂₀-4 contains both the covalent and ionic characters.