Accurate determination of a potential energy surface for CD3H
Accurate determination of a potential energy surface for CD3H
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准确测定 CD3H 的势能面
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
C. Leforestier
中科院分区：
文献类型：
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作者：
C. Iung;C. Leforestier
本文提出了一种应用Lanczos算法从实验光谱拟合势能面的方法。这种方法对传统方法提出了两个明确的改进：（i）Lanczos算法允许处理超大基组（在该计算中有120 000个状态），以及（ii）可以选择性地将计算调整到光谱的特定分量（例如，给定的组合带nνi+mνj），从而大大降低了拟合的复杂性。这种方法已被应用到CD 3 H分子，考虑所有的振动自由度。对于C-H伸缩模的高泛音（高达16 000 cm−1），已经获得了会聚的谱线位置。拟合表面的准确性证明了实验和计算的光谱参数的直接比较。
We present in this paper an application of the Lanczos algorithm to the fitting of a potential energy surface from the experimental spectrum. This method presents two definite improvements on the conventional approach: (i) the Lanczos algorithm allows to treat ultra‐large basis sets (120 000 states in this calculation) and (ii) it is possible to tune selectively the calculation to specific components of the spectrum (e.g., a given combination band nνi+mνj) thus reducing considerably the complexity of the fit. This method has been applied to the CD3H molecule, considering all the vibrational degrees of freedom. Converged line positions have been obtained for high overtones of the C–H stretching mode (up to 16 000 cm−1). The accuracy of the fitted surface is demonstrated by direct comparison of experimental and calculated spectroscopical parameters.