Unbiased Fuzzy Global Optimization with Complex Three-Body Interactions: The Case of Large (C60)N Clusters with the First-Principles PPR Potential.

We propose a simple but robust variant of the fuzzy global optimization method, FGO-3body, to unbiasedly deal with large clusters with complex three-body interactions. For fullerene clusters (C60)N with the first-principles PPR potential energy surfaces, the three-body interactions have posed a major challenge, thus restricting the global optimization studies to cluster sizes of N ≤ 105 so far. In sharp contrast, our new FGO-3body method successfully increases this size to N ≤ 320. The corresponding global minimum structures and energies, magic sizes, and growth patterns have been obtained. In comparison with the results available in the literature for (C60)11 ≤ N ≤ 105, we additionally identify 14 and 3 new clusters with even lower energies using the PPR pair potential (with two-body interactions only) and the PPR potential (with both two-body and three-body interactions), respectively. In particular, after including the three-body interactions, small clusters with icosahedral structures become relatively less favored, and large clusters turn from decahedral to close-packed structures for N = 85, 87, 94, 98, 100, 153, 224, 231, 253, 269, and 285. Thereby, we have shown that FGO-3body is a powerful global structure optimization method for complex clusters.