Unbiased Fuzzy Global Optimization of Fullerene Molecular Clusters with the Challenging Girifalco Potential

By utilizing our recently developed unbiased fuzzy global optimization (FGO) method, here, we systematically study fullerene molecular clusters (C_m)_N with the Girifalco potential for the cluster size 11 ≤ N ≤ 400 and the fullerene size m = 28, 36, 40, 60, 76, 84, and 96. In comparison to the only available results in the literature for (C₆₀)_N with N ≤ 150, the success ratios of global minima are significantly increased by about 2 orders of magnitude by FGO and new structures with lower energies are obtained for (C₆₀)₁₂₉, (C₆₀)₁₃₈, and (C₆₀)₁₄₅. In particular, the magic sizes and growth patterns are identified for all of the investigated fullerene clusters. We find that these clusters tend to be decahedral or close-packed for large N, while the cluster size for the icosahedron-to-decahedron transition decreases with increasing the fullerene size m. Thereby, we show that FGO is a powerful method for the global optimization of molecular clusters, even with the challenging short-range Girifalco potential.