The octad system of methane (12)CH(4) has been analyzed with a fourth-order (459 parameters) Hamiltonian for energy levels and a third-order (28 parameters) dipole moment expansion for infrared intensities. Nearly 8000 assigned positions and 2500 measured line intensities (obtained with the Fourier transform spectrometer located at Kitt Peak National Observatory/National Solar Observatory) have been considered in the modeling. Infrared (Octad-Ground State) and hot bands (Octad-Dyad) data have been used. While the model does not reproduce the measurements at their inherent experimental precisions, it has been sufficient to interpret and substantially assign this spectral region of methane for the first time in over 30 years of investigation. Copyright 2001 Academic Press.

中文翻译：

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12CH4 相互作用的八元系统分析

甲烷 (12)CH(4) 的八元系统已用四阶（459 个参数）哈密顿量分析了能级和三阶（28 个参数）偶极矩扩展的红外强度。建模中考虑了近 8000 个指定位置和 2500 条测量线强度（使用位于 Kitt Peak 国家天文台/国家太阳天文台的傅立叶变换光谱仪获得）。红外（Octad-Ground State）和热波段（Octad-Dyad）数据已被使用。虽然该模型没有以其固有的实验精度重现测量结果，但在 30 多年的调查中，它首次足以解释和实质性地分配甲烷的这个光谱区域。版权所有 2001 学术出版社。