Rh_(13)团簇的几何结构和电子与磁性性质的计算(英文)

利用密度泛函理论,对Rh_(13)团簇的几何结构、电子和磁性性质进行了研究,在优化过程中,其几何结构由正二十面体演化为变形的非对称结构,相邻原子间由等键长变为不等键长.优化后Rh_(13)团簇的结合能比前面的其他研究者所得的结果大得多,这表明变形后的非对称结构比对称的正二十面体结构更为稳定.虽然我们得到的原子平均磁矩较之前面的研究者的结果小了一些,但是仍然比实验结果大,这一情况说明我们所得到的变形的非对称几何结构与真实的未知基态结构仍还有差异.同时我们还发现优化后的Rh_(13)团簇的价带宽度和交换劈裂都有一定程度的展宽和变大,态密度的峰值有远离费米能级向两侧移动的趋势.

Calculations on the geometrical structure, electronic and magnetic properties of Rh13 cluster

Geometrical structure, electronic and magnetic properties of 13-atom Rh cluster has been studied by using DFT method. The geometrical structure of Rh13 cluster evolved from perfect icosahedron to distorted asymmetry structure during the optimizing process, the optimized bond length between adjacent atom changed from equal to unequal. Binding energy we got is much larger than previous works, this indicated that the distorted Rh13 cluster is more stable than perfect symmetry structure. The average magnetic moment per atom in our work is lower than these previously calculated results expectedly, but still larger than experiment result, this discrepancy shows that the distorted structure in our work is still different from real unknown asymmetry ground-state structure and has the tendency to distorted further toward lower symmetry. Comparing with previous works, the valence band width and exchange splitting we got for distorted Rh13 cluster broaden to some extent, the peak of DOS for majority-spin electrons and minority-spin electrons have the tendency of moving far away from EF.