Potential energy surfaces and nonadiabatic transitions in the asymptotic regions of ICN photodissociation to study the interference effects in the F 1 and F 2 spin‐rotation levels of the CN
Potential energy surfaces and nonadiabatic transitions in the asymptotic regions of ICN photodissociation to study the interference effects in the F 1 and F 2 spin‐rotation levels of the CN
复制标题
ICN光解离渐进区的势能面和非绝热跃迁研究CN的F 1 和F 2 自旋旋转能级的干涉效应
DOI：
10.1002/jcc.25736
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发表时间：
2018
影响因子：
3
通讯作者：
Yabushita Satoshi
中科院分区：
文献类型：
--
作者：
Kashimura Tatsuhiko;Ikezaki Tomoya;Ohta Yusuke;Yabushita Satoshi
ICN带光解离最引人注目但尚未解决的问题之一是CN碎片每个旋转能级N的非统计自旋旋转F1 =N+ 1/2和F2 =N− 1/2布居。F1/F2群体差异函数f（N）具有很强的N和λ依赖性，并具有振荡行为。这些细节被发现严重依赖于开放通道产物状态的数量，即I（2 P3/2）和I（2 P1/2）是否作为解离伴侣在能量上可用。首先，在渐近区域中，详细研究了交换和偶极-四极片段间的相互作用。然后，作为非绝热基，我们采取了适当的对称性适应产品的电子和转动波函数的F1和F2水平的解离极限。我们发现绝热哈密顿量表现出Rosen-Zener-Demkov型非绝热跃迁，反映了CN内交换相互作用和小但有限的自旋-旋转相互作用之间的切换。这种非交叉型非绝热跃迁以1/2的概率发生，即在非绝热极限下，通过CN自旋S的量子化轴从解离轴突然切换到CN旋转轴N。我们推导了f（N）和取向参数的半经典公式，其中两态模型包括3A′和4A′电子态，四态模型包括3A′到6A′电子态。这两种干扰模型分别解释了Zare和Hall的F_1和F_2群体的一般特征。© 2018 Wiley Periodicals，Inc.
One of the most spectacular yet unsolved problems for the ICN ‐band photodissociation is the non‐statistical spin‐rotationF1=N+ 1/2 andF2=N− 1/2 populations for each rotation levelNof the CN fragment. TheF1/F2population difference functionf(N) exhibits strongNandλdependences with an oscillatory behavior. Such details were found to critically depend on the number of open‐channel product states, namely, whether both I (2P3/2) and I (2P1/2) are energetically available or not as the dissociation partner. First, in the asymptotic region, the exchange and dipole‐quadrupole inter‐fragment interactions were studied in detail. Then, as the diabatic basis, we took the appropriate symmetry adapted products of the electronic and rotational wavefunctions for theF1andF2levels at the dissociation limits. We found that the adiabatic Hamiltonian exhibits Rosen–Zener–Demkov type nonadiabatic transitions reflecting the switch between the exchange interaction and the small but finite spin‐rotation interaction within CN at the asymptotic region. This non‐crossing type nonadiabatic transition occurs with the probability 1/2, that is, at the diabatic limit through a sudden switch of the quantization axis for CN spinSfrom the dissociation axis to the CN rotation axisN. We have derived semiclassical formulae forf(N) and the orientation parameters with a two‐state model including the 3A′ and 4A′ electronic states, and with a four‐state model including the 3A′ through 6A′ electronic states. These two kinds of interfering models explain general features of theF1andF2level populations observed by Zare's group and Hall's group, respectively. © 2018 Wiley Periodicals, Inc.