Anisotropy effect on global minimum structures of clusters: two-center Lennard-Jones model.
Using a two-center Lennard-Jones (2CLJ) model, the simplest anisotropic case, we investigated how anisotropy affects global minimum structures of clusters and obtained some interesting results. The anisotropy parameter, R, is defined as the ratio of the bond length of 2CLJ dimer to the LJ equilibrium pair separation, where a larger R value means higher anisotropy. For low R values, the structures resemble those of the Lennard-Jones atomic clusters. However, as the pairwise interaction becomes more anisotropic, the "magic numbers" change, and several novel cluster patterns emerge as particularly stable structures, and the global minima change from icosahedral, to polyicosahedral and to novel irregular structures. Moreover, increasing the anisotropy effectively softens the 2CLJ potential. Given the general importance of the LJ cluster as a simple model cluster, 2CLJ model can provide a straightforward and useful analysis of the effect of molecular shape on the structures of clusters.
Hefei National Laboratory for Physical Sciences at the Microscale, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China. fy@ustc.edu
Yan
Y
Feng
Jing
J
Wu
Longjiu
L
Cheng
Haiyan
H
Liu