Geometric and electronic structures of (BeO)(N) (N = 2-12, 16, 20, and 24): rings, double rings, and cages.

The structure of (BeO)(N) clusters (N = 2-12, 16, 20, and 24) are investigated using the method combining the genetic algorithm with density function theory. Benchmark calculation indicates that THSSh functional is reliable to predict the structures of (BeO)(N) cluster. The global minimum structures of (BeO)(N) clusters are rings up to N = 5, double rings at N = 6 and 7 and cages at N ≥ 8. Besides, almost all of the structures of (BeO)(N) cluster are aromatic according to the NICS criterion. Adaptive natural density partitioning analysis reveals that C(6), (BN)(3), and (BeO)(3) rings (C(24) and (BeO)(12) fullerenes) are similar in bonding patterns. The building-up principle of (BeO)(N) is different from that of covalent (BN) and ionic (LiF and MgO) clusters.