Zn{i}O{i}集群的电子激发能量
Jon M Matxain1, Jose M Mercero, Joseph E Fowler
1Kimika Fakultatea, Euskal Herriko Unibertsitatea, P.K. 1072, 20018 Donostia, Euskadi, Spain. pobmabej@sq.ehu.es
Journal of the American Chemical Society
|August 2, 2003
概括
时间依赖密度功能理论 (TDDFT) 的计算揭示了氧化集群的激发能. 环状星团表现出比3D星团更高的能量,3D结构接近可见光谱.
科学领域:
- 计算化学计算化学
- 材料科学 材料科学 材料科学
- 量子力学就是量子力学.
背景情况:
- 氧化 (ZnO) 集群在催化和半导体研究中至关重要.
- 了解它们的电子特性,特别是激发能,是设计新材料的关键.
- 以前的研究通常集中在较小的集群或不同的理论方法.
研究的目的:
- 计算和分析小氧化 (Zn(i) O(i)) 集群 (i=1-15) 在它们的全球最小值的激发能.
- 调查集群几何学 (环状与3D) 对激发能量的影响.
- 为了比较不同密度函数的准确性来预测这些能量.
主要方法:
- 采用时间依赖密度函数理论 (TDDFT) 进行电子激发能计算.
- 使用了相对论的紧有效核心潜力和扩展的SKBJ基础集.
- 将TDDFT结果与基于使用MPW1PW91和B3LYP函数的Kohn-Sham自值差异的计算进行了比较.
主要成果:
- 计算的激发能量通常来自氧气的非结合性p轨道.
- 环状ZnO集群的激发能量比3D集群的激发能量高.
- 3D星团的激发能量属于可见光谱范围.
- 与TDDFT相比,B3LYP功能表现出比MPW1PW91更高的准确性.
- 随着集群规模的增加,Kohn-Sham固有价值之间的差异接近TDDFT值.
结论:
- 集群几何学显著影响激发能量,3D结构显示了可见光应用的潜力.
- 与MPW1PW91.1.相比,B3LYP为激发能量提供了更准确的近似值.
- 使用Kohn-Sham固有值差异是一种可行且实用的方法,用于估计较大的ZnO集群中的激发能.
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