Xu Zijian, Han Jiaguang, Zhu Zhiyuan, Zhang Wei
Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China.
J Phys Chem A. 2007 Feb 1;111(4):656-65. doi: 10.1021/jp064500b.
The energetic and electronic properties of D5h C50 before and after passivation by H or Cl are investigated using first-principle computational method of density functuional theory with generalized gradient approximation and local density approximation functionals. The results show that H or Cl addition can lead to energetic stabilization. Additions also increase the highest occupied molecular orbit-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of C50 fullerides and make them chemically more stable. In the series of C50H2m (m = 0 approximately 7), the Saturn-shaped D5h C50H10 has the largest HOMO-LUMO gap, which suggests that such a structure of C50H10 is a "magic-number" stable one of C50 adducts, and ten is a pseudovalence or effective valence of C50 fullerene pseudoatom. This point also is supported by the energetic properties of C50H2m series such as binding energies, etc. A minimal energy reaction pathway is constructed to get C50H10 and C50H14. Some useful experience for determining the favorable addition sites was summarized. A simple steric method is developed to predict the effective valences of classical fullerenes.
采用密度泛函理论的第一性原理计算方法，结合广义梯度近似和局域密度近似泛函，研究了H或Cl钝化前后D5h C50的能量和电子性质。结果表明，添加H或Cl可导致能量稳定。添加物还增加了C50富勒化物的最高占据分子轨道-最低未占据分子轨道（HOMO-LUMO）能隙，并使其化学稳定性更高。在C50H2m（m = 0至7）系列中，土星状的D5h C50H10具有最大的HOMO-LUMO能隙，这表明C50H10的这种结构是C50加合物的一种“幻数”稳定结构，且10是C50富勒烯假原子的一个假价或有效价。这一点也得到了C50H2m系列的能量性质（如结合能等）的支持。构建了得到C50H10和C50H14的最小能量反应途径。总结了一些确定有利加成位点时有用的经验。开发了一种简单的空间方法来预测经典富勒烯的有效价。
