Structural Evolution and Electronic Properties of Neutral Boron-Doped Nitrogen Clusters.

Clusters represent intermediate states between isolated atoms and bulk solids. They serve as model systems to elucidate the physical properties of compounds from the atomic or molecular scale to the macroscopic bulk phase. Here, we perform thorough structure searches of neutral boron doped nitrogen clusters by Crystal structural anaLYsis by Particle Swarm Optimization (CALYPSO) cluster structural prediction and density functional theory (DFT) calculations. The calculated results indicate that the ground state structures of BNn (n = 4-16) clusters are evolutional from one-dimensional (1D) chains to two dimensional (2D) rings, and finally to three-dimensional (3D) geometries. Interestingly, the intriguing BN12 cluster, characterized by a 3D configuration with a central boron atom connecting four N3 chains in distinct directions, exhibits exceptional stability. The chemical bonding analysis reveals that the outstanding stability of BN12 cluster is attributed to the strong σ and π interactions between the 2p orbitals of the boron atom and the surrounding nitrogen atoms, as well as the robust σ bonds along the four nitrogen chains. The present findings offer important insights for understanding the geometries and electronic properties of neutral boron doped nitrogen clusters and provide an avenue for the design and synthesis of nitrogen-rich compounds. .