Modeling vibrational spectra using the self-consistent charge density-functional tight-binding method. I. Raman spectra
Modeling vibrational spectra using the self-consistent charge density-functional tight-binding method. I. Raman spectra
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DOI：
10.1063/1.1775787
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发表时间：
2004-09-15
影响因子：
4.4
通讯作者：
Stradomska, A
中科院分区：
文献类型：
--
作者：
Witek, HA;Morokuma, K;Stradomska, A
本文提出了一种扩展的自洽电荷密度-泛函紧束缚(SCC-DFTB)方法，它允许计算超大分子振动拉曼光谱中的峰强度。这个扩展是基于一个简单的ANSAZ：在SCC-DFTB能量表达式中增加了一个额外的项，它描述了外部电场与诱导的原子电荷的相互作用。我们应用改进的SCC-DFTB方法重现了17个有机分子的振动拉曼光谱。计算的光谱与实验和密度泛函理论(DFT)计算得到的光谱进行了比较。我们发现，SCC-DFTB方法能够重现实验拉曼光谱的大部分特征。分析了这种方法的局限性和优点，并提出了解释计算的SCC-DFTB拉曼光谱的建议。(C)2004年美国物理研究所。
An extension of the self-consistent charge density-functional tight-binding (SCC-DFTB) method is presented that allows for calculating intensities of peaks in vibrational Raman spectra for very large molecules. The extension is based on a simple ansatz: an extra term, which describes interaction of an external electric field with induced atomic charges, is added to the SCC-DFTB energy expression. We apply the modified SCC-DFTB formalism for reproducing vibrational Raman spectra of 17 organic molecules. The calculated spectra are compared with experiment and with spectra obtained from density functional theory (DFT) calculations. We find that the SCC-DFTB method is capable of reproducing most of the features of experimental Raman spectra. Limitations and advantages of this approach are analyzed and suggestions for interpreting calculated SCC-DFTB Raman spectra are given. (C) 2004 American Institute of Physics.