A theoretical study of multidimensional nuclear tunneling in malonaldehyde
A theoretical study of multidimensional nuclear tunneling in malonaldehyde
复制标题
丙二醛多维核隧道效应的理论研究
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
J. Almlöf
中科院分区：
文献类型：
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作者：
Norihiro Shida;P. Barbara;J. Almlöf
最近Carrington和Miller在反应面哈密顿框架下对丙二醛分子内质子转移的各个方面进行了理论研究，并将二维表面应用于丙二醛分子。目前的计算包括三维反应面和高水平的从头计算精度，给出了比实验小∼50%的隧道分裂和在没有可调参数的情况下氢/氚同位素效应在实验40%以内。分析了振动波函数，提取了超曲面上的有效曲线隧穿路径。路径计算和其他分析清楚地证明了丙二醛等多原子隧道系统的一维模型的局限性。此外，还计算了丙二醛激发振动态的隧道分裂，从而对质子转移的多维性质有了新的认识。
Various aspects of the intramolecular proton transfer in malonaldehyde have been investigated theoretically within the reaction surface Hamiltonian framework, which was recently applied with a two‐dimensional surface to this molecule by Carrington and Miller. The present calculation, which involves a three‐dimensional reaction surface and a high level of ab initio accuracy, gives a tunneling splitting which is ∼50% smaller than experiment and a hydrogen/deuterium isotope effect that is within 40% of experiment with no adjustable parameter. The vibrational wave function has been analyzed to extract an effective curvilinear tunneling path on the hypersurface. The path calculations, and other analysis, clearly demonstrate the limitations of one‐dimensional models for polyatomic tunneling systems like malonaldehyde. In addition, tunneling splittings have been calculated for excited vibrational states of malonaldehyde, leading to new insight into the multidimensional character of proton transfer.