The SiH2D2 asymmetric top has nine vibrational modes, five of them forming a pentad strongly perturbed by Coriolis interactions. High-level ab initio calculations of SiH2D2 have been performed which yield numerous spectroscopic parameters related to the harmonic and anharmonic force fields. The bending pentad comprising nu4(A1), nu7(B1), nu5(A2), nu9(B2), and nu3(A1) has been studied by high-resolution Fourier transform spectroscopy; the region 600-1050 cm-1 has been investigated with a resolution of ca. 4 x 10(-3) cm-1. Raman BOXCARS spectroscopy has been used for the infrared inactive nu5 band. The Raman apparatus function was 0.0054 cm-1. Assignments of about 4000 transitions including all bands have been made, mostly employing ground state combination differences techniques, and a global fit has been performed. The fundamentals nu4 (681.624 cm-1), nu7 (742.640 cm-1), nu5 (842.381 cm-1), nu9 (859.750 cm-1), and nu3 (942.741 cm-1) are strongly coupled by A-, B-, and C-type Coriolis interactions, and ab initio predictions of these interaction parameters were used to set up a network of interactions that was refined by the experimental data. The global standard deviation for the entire body of data is 7.1 x 10(-4) cm-1. Satisfactory synthetic spectra which are very sensitive to relative signs of dipole moment derivatives and Coriolis interaction constants were obtained with the guidance of ab initio calculations. Finally, fair to good agreement of experimental and ab initio calculated molecular parameters was obtained. For the first time, a complete analysis of the pentad of SiH2D2 in the 10-16 µm region has been carried out. A full set of rovibrational parameters is given for these five interacting levels, including first and second order Coriolis interaction constants. Copyright 1998 Academic Press.

中文翻译：

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SiH2D2 弯曲五元组在 10–16 μm 区域的 Ab InitioCalculations 和高分辨率光谱

SiH2D2 不对称顶部有九个振动模式，其中五个形成受到科里奥利相互作用强烈扰动的五元组。已经执行了 SiH2D2 的高级从头计算，产生了许多与谐波和非谐波力场相关的光谱参数。通过高分辨率傅里叶变换光谱研究了由nu4(A1)、nu7(B1)、nu5(A2)、nu9(B2)和nu3(A1)组成的弯曲五元组；600-1050 cm-1 的区域已被研究，分辨率为约。4 x 10(-3) cm-1。拉曼 BOXCARS 光谱已用于红外非活性 nu5 波段。拉曼仪器函数为 0.0054 cm-1。已经进行了大约 4000 次转换的分配，包括所有波段，主要采用基态组合差异技术，并进行了全局拟合。基本原理 nu4 (681. 624 cm-1)、nu7 (742.640 cm-1)、nu5 (842.381 cm-1)、nu9 (859.750 cm-1) 和 nu3 (942.741 cm-1) 通过 A-、B- 和 C 强耦合型科里奥利相互作用和这些相互作用参数的从头预测被用来建立一个由实验数据改进的相互作用网络。整个数据主体的全局标准偏差为 7.1 x 10(-4) cm-1。在 ab initio 计算的指导下获得了对偶极矩导数和科里奥利相互作用常数的相对符号非常敏感的令人满意的合成光谱。最后，获得了实验和从头计算的分子参数的公平到良好的一致性。首次对 10-16 µm 区域的 SiH2D2 五元组进行了完整分析。给出了这五个相互作用水平的全套振动参数，包括一阶和二阶科里奥利相互作用常数。版权所有 1998 学术出版社。