(湖南大学 材料科学与工程学院， 长沙 410082)
摘 要: 采用第一原理赝势平面波方法计算Aln(n=2~24, 55)团簇的几何、 能态与电子结构， 通过结合能Eb、 HOMO-LUMO能隙ΔEH-L与能量二阶差分Δ2E(n)表征和考察团簇原子数n对Aln团簇基态结构稳定性的影响。 结果表明： Aln团簇结构稳定性随团簇原子数n增加而增大， 并在n为7, 11, 13, 19, 23等近幻数和高对称性结构处出现极值， 相对其临近Aln团簇， 具有较高的结构稳定性。 DOS与吸收光谱分析表明， 随着团簇内部s-p电子杂化的逐渐增强， Aln团簇结构的稳定性也随之增加， 但即使当团簇原子数n达到55时， 其微弱的表面效应仍不能消除。
关键字: 赝势平面波方法； Aln团簇； 电子结构； 结构稳定性
（School of Materials Science and Engineering, Hunan University,Changsha 410082, China）
Abstract: The geometries, energetics and electronic structure of neutral Aln(n=2-24, 55) clusters were calculated using the first-principles pseudo-potential plane wave method. The several parameters, such as binding energy Eb, HOMO-LUMO energy gap ΔEH-L, second difference of energies Δ2E(n) were utilized to characterize and analyze the structure stability of Aln cluster. The results show that the structure stability of Aln clusters increases with the increase of total atom number n. For Al7, Al11, Al13, Al19, Al23 clusters with nearly filled shell of the covalence electron number and high symmetry of geometrical structure, a high structure stability relative to their neighbor Aln clusters can be seen. The analysis of the DOS and absorption spectra shows that the increase of stability of Aln cluster mainly originates from the enhancement of s-p hybridization of Al atoms in cluster, but when up to n=55, the weak influences of surface energy caused by the size of cluster on the properties of Aln cluster can not be eliminated still.
Key words: pseudo-potential plane-wave method; Aln cluster; electronic structure; structural stability
