Theoretical Prediction of Size-Dependent Structures and Properties for the Asymmetric Clusters (HBrInN3)n (n = 1–6)

Abstract

In order to search single-source precursors (SSP) for InN material, the structures, relative stabilities, and electronic properties of small asymmetric clusters (HBrInN3)n (n = 1–6) are systematically investigated at the B3LYP level. The optimized clusters all contain cyclic structures (InNα)n and prefer 3-dimensional configurations for n = 2–6. The uncorrected binding energies (Eb), corrected binding energies (Eb-c) and average corrected binding energies (Eb-c-ave) all reveal that all asymmetric clusters (HBrInN3)n (n = 1–6) can continue to gain energy with the cluster size n increasing. The relative stabilities of clusters (HBrInN3 )n (n= 1–6) are analysed based on the second-order difference of energy (Δ2E) and HOMO–LUMO energy gap (Egap). It is found that the Δ2E exhibits a pronounced even–odd alternation phenomenon with variation of the cluster size n. Compared with monomer HBrInN3, the N–N asymmetric stretching of N3 groups for asymmetric clusters (HBrInN3)n (n = 2–6) shows blue-shifted, however, the N–N symmetric stretching of N3 groups and In–H stretching vibration exhibit red-shifted, respectively. Thermodynamic properties increase linearly with the cluster size n as well as the temperature. The transformations of the clusters (HBrInN3)n (n = 2–6) from the monomer are thermodynamically favorable at 298.2 K judged by Gibbs free energies.