Anharmonic Vibrational Motions In C60: A Potential Energy Surface Derived From Vibrational Self-Consistent Field Calculations
Anharmonic Vibrational Motions In C60: A Potential Energy Surface Derived From Vibrational Self-Consistent Field Calculations
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C60 中的非简谐振动：由振动自洽场计算得出的势能面
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Allen Broughton
中科院分区：
文献类型：
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作者：
D. A. Jelski;L. Nemes;Allen Broughton
为 C60 开发了势能面 (PES)，旨在描述非简谐极限下有效的振动运动。 PES 基于先前存在的适合谐波基本原理的 PES，然后进行修改以生成所有阶数和所有项的非谐波，但无需额外的拟合参数。由此产生的笛卡尔振动运动被分解为简正模态，并计算非谐膨胀系数，包括 2 模耦合和高达 4 阶的系数。所得的 PES 用于振动自洽场 (VSCF) 算法，以计算非谐波校正的基频。然后将参数拟合到基本红外和拉曼频率。虽然不可能以足够的实验精度分配组合和泛音转换，但描述了有关 C60 中非谐波振动耦合影响的结论。
A potential energy surface (PES) is developed for C60 designed to describe vibrational motions valid in the anharmonic limit. The PES is based on a previously existing one that is fit to the harmonic fundamentals and is then modified to generate anharmonicity of all orders and in all terms, but without additional fitted parameters. The resulting Cartesian vibrational motions are decomposed into normal modes, and the anharmonic expansion coefficients are calculated including 2-mode couplings and up to 4th order. The resulting PES is used in a vibrational self-consistent field (VSCF) algorithm to calculate the anharmonically corrected fundamental frequencies. The parameters are then fit to fundamental infrared and Raman frequencies. While it is not possible to assign combination and overtone transitions with sufficient experimental accuracy, conclusions about the effects of anharmonic vibrational coupling in C60 are described.