Insights into structural and electronic properties of (LiH)n (n = 5–25) clusters: Density functional calculations

Abstract

First principles calculations have been performed to analyze the structural and electronic properties of (LiH)n clusters by combining an artificial bee colony algorithm within the framework of Density Functional Theory (DFT). The structural analysis shows that with an increase in cluster size, the structural shape tends to become more amorphous in which the lithium (Li) atom occupies the central position, surrounded by hydrogen (H) atoms at the vertex sites. The bond length between Li and H was found to be 1.77–2.01 Å, which is in good agreement with the previous study. Through stability analysis, the calculated formation energy of LiH clusters increase from n = 5 through n = 25. The projected density of states was calculated and analyzed to get deeper insight of the electronic structure. The charge density distribution and results of density derived electrostatic and chemical (DDEC6) analysis revealed ionic bonding characteristics between Li and H atoms, and charge density difference analysis concludes electron transfers from Li to H atoms.