Density functional theory study of geometry and stability of small Zr _n (n = 2-10) clusters

摘要

Geometric structures, electronic properties, and stabilities of small Zr_n and Zrn+ (n = 2-10) clusters have been investigated using density functional theory with effective core potential LanL2DZ basis set. For both neutral and charged systems, several isomers and different multiplicities were studied to determine the lowest energy structures. Many most stable states with high symmetry were found for small Zrn clusters. The most stable structures and symmetries of Zr_n+ clusters are the same as the neutral ones except n = 4 and 7. We found that the clusters with n > 3 possess highly compact structures. The clusters are inclined to form the caged-liked geometry containing pentagonal structures for n > 8, which is in favor of energy. From the formation energy and second-order energy difference, we obtained that 2-, 5-, 7-atoms of neutral and 4-, 7-atoms cationic clusters are the magic numbers. Furthermore, the highest occupied molecular orbital-lowest unoccupied molecular orbital gaps display that the Zr_3, Zr_6, Zr4+, and Zr9+ are more stable in chemical stability.