碳奈米結構理論模型

Abstract

碳奈米結構，包括富樂烯、單層及多層奈米管、奈米錐、碳的洋蔥結構，以及包含多種結構的集合體之多種物理及化學性質，已於理論研究上提出及討論。這些計算將以電荷自洽的密度泛函緊束縛方法 (SCC-DFTB) 進行。SCC-DFTB是一種可用於超過一千個原子的大型系統之密度汎函理論 (DFT) 的近似方法。我們專注於以下的碳奈米結構性質：能量上的穩定度、平衡結構、在有限溫度下的平均結構、振動頻率、不同態的電子及振動密度，以及振動紅外及拉曼光譜。我們特別關注於多樣碳奈米結構，例如碳的洋蔥結構、包含於奈米管中的富樂烯，以及多層奈米管之構成。我們將研究此類集合體的結構與能量性質，並將特別關注於集合體構成過程中的物理以及光譜性質變化。

Theoretical investigation of various physical and chemical properties of carbon nanostructures, including fullerenes, single- and multi-wall nanotubes, nanocones, carbon onions, and aggregates of those structures, is proposed and discussed. The calculations will be performed with the self-consistent-charge density-functional tight-binding (SCC-DFTB) method. SCC-DFTB is an approximated version of DFT that can be applied to systems containing more than 1000 atoms. We focus on the following properties of carbon nanostructures: energetic stability, equilibrium geometries, averaged geometries at finite temperatures, vibrational frequencies, electronic and vibrational densities of states, and vibrational IR and Raman spectra. Special attention is given to the assemblies of various carbon nanostructures, e.g. carbon onions, fullerenes encapsulated in a nanotube, multi-wall nanotubes. Geometry and energetics of these aggregate-type structures will be studied; special attention will be devoted to the change of physical and spectroscopic properties of the assemblies upon aggregation.