Zang Q J, Su Z M, Lu W C, Wang C Z, Ho K M
Institute of Functional Material Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
J Phys Chem A. 2006 Jul 6;110(26):8151-7. doi: 10.1021/jp061517l.
We have performed systematic ab initio calculations to study the structures and stability of Si(6)O(n)() clusters (n = 1-12) in order to understand the oxidation process in silicon systems. Our calculation results show that oxidation pattern of the small silicon cluster, with continuous addition of O atoms, extends from one side to the entire Si cluster. Si atoms are found to be separated from the pure Si cluster one-by-one by insertion of oxygen into the Si-O bonds. From fragmentation energy analyses, it is found that the Si-rich clusters usually dissociate into a smaller pure Si clusters (Si(5), Si(4), Si(3), or Si(2)), plus oxide fragments such as SiO, Si(2)O(2), Si(3)O(3), Si(3)O(4), and Si(4)O(5). We have also studied the structures of the ionic Si(6)O(n)(+/-) (n = 1-12) clusters and found that most of ionic clusters have different lowest-energy structures in comparison with the neutral clusters. Our calculation results suggest that transformation Si(6)O(n)+(a) + O --> Si(6)O(n+1)+(a) should be easier.
为了理解硅体系中的氧化过程，我们进行了系统的从头算计算，以研究Si(6)O(n)()团簇（n = 1 - 12）的结构和稳定性。我们的计算结果表明，随着氧原子的不断添加，小硅团簇的氧化模式从一侧扩展到整个硅团簇。通过在Si - O键中插入氧原子，发现硅原子从纯硅团簇中逐个分离出来。从碎片化能量分析可知，富硅团簇通常分解为较小的纯硅团簇（Si(5)、Si(4)、Si(3)或Si(2)），再加上诸如SiO、Si(2)O(2)、Si(3)O(3)、Si(3)O(4)和Si(4)O(5)等氧化物碎片。我们还研究了离子型Si(6)O(n)(+/-)（n = 1 - 12）团簇的结构，发现与中性团簇相比，大多数离子团簇具有不同的最低能量结构。我们的计算结果表明，转变Si(6)O(n)+(a) + O --> Si(6)O(n + 1)+(a)应该更容易。
