Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA, CNRS UMR 7583), Université Paris Est Créteil, Université Paris Diderot, Institut Pierre-Simon Laplace, 94010 Créteil Cedex, France.
Hefei National Laboratory for Sciences at Microscale, University of Science and Technology of China, 230026 Hefei, China.
J Chem Phys. 2014 Feb 28;140(8):084308. doi: 10.1063/1.4866449.
Room temperature absorption spectra of various transitions of pure CO2 have been measured in a broad pressure range using a tunable diode-laser and a cavity ring-down spectrometer, respectively, in the 1.6 μm and 0.8 μm regions. Their spectral shapes have been calculated by requantized classical molecular dynamics simulations. From the time-dependent auto-correlation function of the molecular dipole, including Doppler and collisional effects, spectral shapes are directly computed without the use of any adjusted parameter. Analysis of the spectra calculated using three different anisotropic intermolecular potentials shows that the shapes of pure CO2 lines, in terms of both the Lorentz widths and non-Voigt effects, slightly depend on the used potential. Comparisons between these ab initio calculations and the measured spectra show satisfactory agreement for all considered transitions (from J = 6 to J = 46). They also show that non-Voigt effects on the shape of CO2 transitions are almost independent of the rotational quantum number of the considered lines.
分别使用可调谐二极管激光器和腔衰荡光谱仪，在 1.6 μm 和 0.8 μm 区域的宽压力范围内，测量了各种纯 CO2 跃迁的室温吸收光谱。通过再量化的经典分子动力学模拟计算了它们的光谱形状。从包括多普勒和碰撞效应的分子偶极子的时变自相关函数，直接计算光谱形状，而不使用任何调整参数。对使用三种不同各向异性分子间势能计算的光谱进行分析表明，纯 CO2 谱线的形状（洛伦兹展宽和非 Voigt 效应）略微取决于所使用的势能。这些从头算计算与测量光谱之间的比较表明，所有考虑的跃迁（从 J = 6 到 J = 46）都具有令人满意的一致性。它们还表明，CO2 跃迁形状的非 Voigt 效应几乎与所考虑谱线的转动量子数无关。
