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 cluster structural prediction and density functional theory calculations. The calculated results indicate that the ground state structures of BN<i>_n</i>(<i>n</i>= 4-16) clusters are evolutional from one-dimensional chains to two dimensional rings, and finally to three-dimensional (3D) geometries. Interestingly, the intriguing BN₁₂cluster, characterized by a 3D configuration with a central boron atom connecting four N₃chains in distinct directions, exhibits exceptional stability. The chemical bonding analysis reveals that the outstanding stability of BN₁₂cluster is attributed to the strong<i>σ</i>and<i>π</i>interactions between the 2<i>p</i>orbitals of the boron atom and the surrounding nitrogen atoms, as well as the robust<i>σ</i>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.