Symmetric double proton tunneling in formic acid dimer: A diabatic basis approach
Symmetric double proton tunneling in formic acid dimer: A diabatic basis approach
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DOI：
10.1021/jp075376e
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发表时间：
2008-01-17
影响因子：
3.3
通讯作者：
Sibert, Edwin L., III
中科院分区：
文献类型：
--
作者：
Barnes, George L.;Squires, Shane M.;Sibert, Edwin L., III
利用反应表面哈密顿量建立了双质子在甲酸二聚体中的隧穿模型。表面包括对称氢氧根拉伸加上平面内拉伸和弯曲中间体振动。表面哈密顿量与在D-2h过渡态结构上得到的5个a、、和B-3g正态模相耦合。采用Davidson和block-Davidson迭代法计算特征态。在反应表面的隧道分裂中发现了强模式特异性效应，其中分裂在中间二聚体弯曲运动的激发下增强。结果是在反应表面模式的非绝热表示框架内解释的。观察到的反应表面特征态的分裂模式在与槽态耦合时只有轻微的改变。还确定了浴状态的分裂模式。发现由于二聚体间弯曲态的微妙混合，预测这些分裂是非常复杂的。
A model of double proton tunneling in formic acid dimer is developed using a reaction surface Hamiltonian. The surface includes the symmetric OH stretch plus the in-plane stretch and bend interdimer vibrations. The surface Hamiltonian is coupled to a bath of five A,, and B-3g normal modes obtained at the D-2h transition state structure. Eigenstates are calculated using Davidson and block-Davidson iterative methods. Strong mode specific effects are found in the tunneling splittings for the reaction surface, where splittings are enhanced upon excitation of the interdimer bend motion. The results are interpreted within the framework of a diabatic representation of reaction surface modes. The splitting patterns observed for the reaction surface eigenstates are only slightly modified upon coupling to the bath states. Splitting patterns for the bath states are also determined. It is found that predicting these splittings is greatly complicated by subtle mixings with the inter-dimer bend states.