Comparison of the Huggins Band for Six Ozone Isotopologues: Vibrational Levels and Absorption Cross Section

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• 作者：Steve Alexandre Ndengu茅 ; Reinhard Schinke ; Fabien Gatti ; Hans-Dieter Meyer ; R茅my Jost
• 刊名：The Journal of Physical Chemistry A
• 出版年：2012
• 出版时间：December 20, 2012
• 年：2012
• 卷：116
• 期：50
• 页码：12260-12270
• 全文大小：529K
• 年卷期：v.116,no.50(December 20, 2012)
• ISSN：1520-5215

文摘

By use of the 3¹A鈥?ab initio potential energy surface (PES) of ozone and the multi-configuration time-dependent Hartree program for wavepacket propagation, we have determined numerous eigenstates of this state for six ozone isotopologues. These bound vibrational levels are the upper levels of the Huggins band, which covers the range from 27鈥?00 to 33鈥?00 cm^鈥?. This study extends our previous work on the Hartley band, which was limited to the range 32鈥?00鈥?0鈥?00 cm^鈥?. Four isotopologues, ¹⁶O₃, ¹⁶O¹⁷O¹⁶O, ¹⁶O¹⁸O¹⁶O, and ¹⁸O₃ (noted hereafter 666, 676, 686, and 888), are symmetric, and two are asymmetric, ¹⁷O¹⁶O₂ and ¹⁸O¹⁶O₂ (noted hereafter 667 and 668). The PES of the 3¹A鈥?state has two equivalent minima of C_s symmetry located at 27鈥?00 cm^鈥? above the X¹A₁ ground state. The equilibrium geometry of these two minima is r_e1 = 2.28 a₀, r_e2 = 3.2 a₀, and 胃_e = 107掳. The dissociation limit of this PES, which correlates to the O(¹D) + O₂ (¹螖) 鈥渟inglet鈥?channel, is about 4300 cm^鈥? above the two minima. For the ¹⁶O₃ isotopologue, the 120 lowest bound eigenstates have been calculated and partially assigned up to 800 cm^鈥? below the dissociation limit. The 60 lower eigenstates are easily assignable in term of three normal modes, the 鈥渓ong鈥?bond (谓₁), the bending (谓₂), and the 鈥渟hort鈥?bond (谓₃). A new family of wave functions, aligned along the dissociation channels, appears at 3782 cm^鈥? above the 3¹A鈥?(0,0,0) level. The 3¹A鈥?vibrational levels and the corresponding intensity factors from the (000), (010), (100), and (001) levels of the X¹A₁ ground state have been calculated for the six isotopologues. The Huggins absorption cross sections of the six isotopologues have been calculated from the 3¹A鈥?vibrational energy levels and the corresponding intensity factors. The rotational envelope of each vibronic band has been empirically described by an ad hoc function. The ratio of the Huggins cross section of each ozone isotopologue with one of ¹⁶O₃ provides the fractionation factor of each ozone isotopologue as a function of the photon energy. These various fractionation factors will allow predicting enrichments due to photolysis by various light sources like the actinic flux.