Full-dimensional quantum dynamics of vibrationally mediated photodissociation of NH3 and ND3 on coupled ab initio potential energy surfaces: absorption spectra and NH2(Ã(2)A1)/NH2(X̃(2)B1) branching ratios.
Full-dimensional quantum dynamics of vibrationally mediated photodissociation of NH3 and ND3 on coupled ab initio potential energy surfaces: absorption spectra and NH2(Ã(2)A1)/NH2(X̃(2)B1) branching ratios.
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DOI：
10.1021/jp5057122
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发表时间：
2014-07
期刊：
影响因子：
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通讯作者：
Jianyi Ma;Changjian Xie;Xiaolei Zhu;D. Yarkony;D. Xie;Hua Guo
中科院分区：
文献类型：
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作者：
Jianyi Ma;Changjian Xie;Xiaolei Zhu;D. Yarkony;D. Xie;Hua Guo
振动介导的NH3和ND3在A波段的光解作用允许在这些多原子体系的基态振动无法到达的区域探索激发态势能面。利用我们最近开发的准绝热表示的耦合从头算势能面，我们在这里报告了振动激发NH3和ND3的Ã←X→吸收光谱的全维量子表征以及相应的NH2（Ã（2)A1） + H和NH2(X→2)B1） + H通道的非绝热解离动力学。吸收光谱中的预解离共振被赋予了适当的量子数。NH2（Ã(2)A1）/NH2（X²(2)B1）支化比对光解前的初始振动激发有轻微的敏感性。讨论了解释实验数据的意义。
Vibrationally mediated photodissociation of NH3 and ND3 in the A band allows the exploration of the excited-state potential energy surface in regions that are not accessible from the ground vibrational state of these polyatomic systems. Using our recently developed coupled ab initio potential energy surfaces in a quasi-diabatic representation, we report here a full-dimensional quantum characterization of the à ← X̃ absorption spectra for vibrationally excited NH3 and ND3 and the corresponding nonadiabatic dissociation dynamics into the NH2(Ã(2)A1) + H and NH2(X̃(2)B1) + H channels. The predissociative resonances in the absorption spectra have been assigned with appropriate quantum numbers. The NH2(Ã(2)A1)/NH2(X̃(2)B1) branching ratio was found to be mildly sensitive to the initial vibrational excitation prior to photolysis. Implications for interpreting experimental data are discussed.