密度泛函理论研究SinMn (n=2～14)团簇的结构和电子性质

采用密度泛函理论中的广义梯度近似对SinMn (n=2～14) 团簇的几何构型进行优化,并对能量、频率和电子性质进行了计算. 结果表明,当n≥10时,Mn原子完全陷入Si原子形成的笼内.二阶能量差分、分裂能和垂直电离势都表明Si5Mn和Si12Mn是稳定的团簇,且12是团簇的幻数.通过对电子性质的分析发现Si12Mn团簇具有较高的化学稳定性.布局数分析表明,在Si5Mn团簇中Mn原子的磁矩(3.923 μB)是最大的.较多的电荷转移以及Mn原子的4s, 3d态和Si原子的3s, 4p态的较强杂化是导致Mn原子磁矩减小的原因.当n≥7时,SinMn 的总磁矩是1 μB.

Density functional theory study on geometries and electronic properties of SinMn (n=2～14) clusters

The geometries and electronic properties of SinMn (n=2～14) clusters have been systematically investigated by using density functional approach. The results indicate Mn atom is fully encapsulated by the Si cages starting from Si10Mn. The second-order energy difference, the fragmentation energies and vertical potential of SinMn clusters manifest that Si5Mn and Si12Mn are the most stable among studied clusters, and the magic numbers of clusters is 12. The Si12Mn cluster possesses strong chemical stability by analyzing the electronic properties. The magnetic moment of Mn atom in Si5Mn clusters (3.923 μB) is largest among all clusters, the more charge transfer and the strong hybridization between 4s, 3d states of Mn and 3s, 4p states of Si might be one major reason for the decreasing magnetic moment of Mn atom. The total magnetic moment of SinMn clusters is about 1 μB with the size of n≤7.