Groupe de Spectrométrie Moléculaire et Atmosphérique UMR CNRS 7331, UFR Sciences BP 1039, 51687 Reims Cedex 2, France.
QUAMER Laboratory, Tomsk State University, Tomsk 634050, Russia.
J Chem Phys. 2017 Feb 14;146(6):064304. doi: 10.1063/1.4973977.
Ab initio dipole moment surfaces (DMSs) of the ozone molecule are computed using the MRCI-SD method with AVQZ, AV5Z, and VQZ-F12 basis sets on a dense grid of about 1950 geometrical configurations. The analytical DMS representation used for the fit of ab initio points provides better behavior for large nuclear displacements than that of previous studies. Various DMS models were derived and tested. Vibration-rotation line intensities of O were calculated from these ab initio surfaces by the variational method using two different potential functions determined in our previous works. For the first time, a very good agreement of first principle calculations with the experiment was obtained for the line-by-line intensities in rotationally resolved ozone spectra in a large far- and mid-infrared range. This includes high overtone and combination bands up to ΔV = 6. A particular challenge was a correct description of the B-type bands (even ΔV values) that represented major difficulties for the previous ab initio investigations and for the empirical spectroscopic models. The major patterns of various B-type bands were correctly described without empirically adjusted dipole moment parameters. For the 10 μm range, which is of key importance for the atmospheric ozone retrievals, our ab initio intensity results are within the experimental error margins. The theoretical values for the strongest lines of the ν band lie in general between two successive versions of HITRAN (HIgh-resolution molecular TRANsmission) empirical database that corresponded to most extended available sets of observations. The overall qualitative agreement in a large wavenumber range for rotationally resolved cold and hot ozone bands up to about 6000 cm is achieved here for the first time. These calculations reveal that several weak bands are yet missing from available spectroscopic databases.
使用 MRCI-SD 方法，结合 AVQZ、AV5Z 和 VQZ-F12 基组，在大约 1950 个几何构型的密集网格上计算臭氧分子的从头算偶极矩表面（DMS）。用于拟合从头算点的分析 DMS 表示在大核位移方面的表现优于以前的研究。推导并测试了各种 DMS 模型。通过我们之前的工作中确定的两种不同的势能函数，从这些从头算表面通过变分法计算 O 的振动-转动谱线强度。首次在远和中红外大范围内旋转分辨的臭氧光谱中，通过第一性原理计算获得了与实验非常吻合的线线强度。这包括高达ΔV=6 的高泛频和组合带。一个特别的挑战是正确描述 B 型带（甚至ΔV 值），这对于之前的从头算研究和经验光谱模型来说是一个主要的难点。在没有经验调整偶极矩参数的情况下，正确描述了各种 B 型带的主要模式。对于对大气臭氧反演至关重要的 10μm 范围，我们的从头算强度结果在实验误差范围内。ν 带最强线的理论值通常介于 HIgh-resolution molecular TRANsmission（HITRAN）经验数据库的两个连续版本之间，这两个版本对应于最广泛的可用观测集。首次在一个大波数范围内实现了冷和热臭氧带的旋转分辨的整体定性一致，范围约为 6000cm。这些计算表明，现有的光谱数据库中还缺少几个弱谱线。
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