Department of Chemistry & Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States.
J Phys Chem A. 2010 Dec 9;114(48):12701-8. doi: 10.1021/jp105354n. Epub 2010 Nov 9.
DFT/TDDFT calculations have been carried out for a series of silver and gold nanorod clusters (Ag(n), Au(n), n = 12-120) whose structures are of cigar-type. Pentagonal Ag(n) clusters with n = 49-121 and hexagonal Au(n) clusters with n = 14-74 were also calculated for comparison. Metal-metal distances, binding energies per atom, ionization potentials, and electron affinities were determined, and their trends with cluster size were examined. The TDDFT calculated excitation energies and oscillator strengths were fit by a Lorentz line shape modification, which gives rise to the simulated absorption spectra. The significant features of the experimental spectra for actual silver and gold nanorod particles are well reproduced by the calculations on the clusters. The calculated spectral patterns are also in agreement with previous theoretical results on different-type Ag(n) clusters. Many differences in the calculated properties are found between the Ag(n) and Au(n) clusters, which can be explained by relativistic effects.
已针对一系列具有雪茄型结构的银和金纳米棒团簇（Ag(n)、Au(n)，n = 12-120）进行了密度泛函理论/含时密度泛函理论计算。还计算了具有 n = 49-121 的五边形 Ag(n)团簇和具有 n = 14-74 的六边形 Au(n)团簇，以便进行比较。确定了金属-金属距离、每个原子的结合能、电离势和电子亲和能，并研究了它们随团簇尺寸的变化趋势。通过洛伦兹线形状修正对 TDDFT 计算出的激发能和振子强度进行拟合，从而得到模拟的吸收光谱。实际银和金纳米棒颗粒的实验光谱的显著特征通过对团簇的计算得到了很好的再现。计算出的光谱模式也与以前关于不同类型 Ag(n)团簇的理论结果一致。在 Ag(n)和 Au(n)团簇之间发现了许多计算性质的差异，这可以用相对论效应来解释。
