The absorption spectrum of the 13CH4 methane isotopologue was recorded on a Bruker IFS-125HR Fourier transform spectrometer at 298 K in the 4970–6200 cm−1 range. In this paper we report the results of assignment and modelling of the line positions and intensities of 13CH4 in the range of weaker absorption between 4970 and 5300 cm−1, corresponding to the lower part of Tetradecad, dominated by the 4ν4 band system near 5180 cm−1. The empirical list in this spectral range contains 1642 lines. Using an effective Hamiltonian initially derived from the analyses of cold Fourier transform (4970–5853 cm−1) and laser direct absorption (5853–6200 cm−1) spectra of the 13CH4, we assigned 1600 lines belonging to four bands of the Tetradecad up to Jmax=16. The 1548 line positions were fitted with an rms deviation of 1.7 × 10−3 cm−1. Measured line intensities were modeled for 674 transitions using the effective dipole transition moments to an rms deviation of about 7 %. The new data were used for the simultaneous global fit of the 13CH4 Hamiltonian parameters for the {Ground state / Dyad / Pentad / Octad / Tetradecad} system and the dipole moment parameters for the {Ground state - Tetradecad} system.

中文翻译：

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在 4970–5300 cm-1 范围内 Tetradecad 下部 298 K 下 13CH4 光谱的分配和建模


13CH4 甲烷同位素体的吸收光谱是在 298 K 的 4970-6200 cm-1 范围内用布鲁克 IFS-125HR 傅里叶变换光谱仪记录的。在本文中，我们报告了 13CH4 在 4970 和 5300 cm-1 之间较弱吸收范围内的线位置和强度的分配和建模结果，对应于 Tetradecad 的下部，以 5180 cm-1 附近的 4ν4 波段系统为主。此光谱范围内的实证列表包含 1642 条线。使用最初从对 13CH4 的冷傅里叶变换 （4970–5853 cm-1） 和激光直接吸收 （5853-6200 cm-1） 光谱分析中得出的有效哈密顿量，我们分配了 1600 条属于 Tetradecad 四个波段的线，最高 Jmax=16。1548 个线位置的 rms 偏差为 1.7 × 10-3 cm-1。使用有效偶极子跃迁矩对 674 次跃迁的测得线强度进行建模，其 rms 偏差约为 7 %。新数据用于 {基态 / 二元组 / 五元组 / 八度 / Tetradecad} 系统的 13CH4 哈密顿量参数和 {基态 - Tetradecad} 系统的偶极矩参数的同步全局拟合。