Binary Lennard-Jones atomic clusters: Structural features induced by large-sized atoms

Global-minimum geometries of binary Lennard-Jones clusters (BLJN where N is the number of atoms) are previously elucidated when the size ratio of the large B atom to the small A atom is 1.05–1.3. In the present study, BLJ clusters for larger size ratios (1.4–2.0) are investigated to clarify the structural features. The heuristic method combined with geometrical perturbations and atom-type conversion is developed to search for the global minima of the BLJ clusters. In the lowest-energy geometries of the BLJ clusters (N ⩽ 50), A and B atoms form cores and outer shells, respectively. The existence of fairly large sized atoms induces complicated structural growth sequence patterns (including icosahedron, triangular orthobicupola, cuboctahedron, etc.). New global minima of BLJ59 for s = 1.15, BLJ68 for s = 1.15 and BLJ70 for s = 1.2 are also reported.