Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, USA.
J Phys Chem A. 2010 Jan 28;114(3):1324-33. doi: 10.1021/jp905731h.
A three-dimensional model of the vibrational dynamics of HOONO is investigated. This model focuses on the couplings between the OH stretch vibration and the two torsions. The model is based on electronic energies, calculated at the CCSD(T)/cc-pVTZ level of theory and basis and dipole moment functions calculated at the CCSD/aug-cc-pVDZ level. The resulting points were fit to explicit functional forms, and the energies, wave functions, and intensities were evaluated using an approach in which the OH stretching motion was adiabatically separated from the torsional modes. It is found that the HOON torsion is strongly coupled to both the OONO torsion and OH stretch. Despite this, many of the conclusions that were drawn from earlier two-dimensional treatments, which did not include the OONO torsion, hold up on a semiquantitative level. In addition, we use this model to investigate the assignment of recently reported matrix isolated spectra of HOONO and DOONO. Finally, by comparing the results of this three-dimensional calculation to two-dimensional calculations and to the results of second-order perturbation theory, we investigate the question of how one determines the size of the reduced-dimensional system that is needed to describe the vibrational spectrum of molecules, like HOONO, that contain several large amplitude motions.
HOONO 的振动动力学的三维模型得到了研究。该模型主要关注 OH 伸缩振动和两个扭转之间的耦合。该模型基于电子能量，在 CCSD(T)/cc-pVTZ 理论水平和基础上计算，并基于 CCSD/aug-cc-pVDZ 理论水平计算偶极矩函数。所得点被拟合到显式函数形式，使用一种将 OH 伸缩运动与扭转模式绝热分离的方法来评估能量、波函数和强度。结果表明，HOON 的扭转与 OONO 的扭转和 OH 伸缩都有很强的耦合。尽管如此，许多从早期二维处理中得出的结论，其中不包括 OONO 的扭转，在半定量水平上仍然成立。此外，我们使用该模型来研究最近报道的 HOONO 和 DOONO 矩阵隔离光谱的分配。最后，通过将三维计算的结果与二维计算和二阶微扰理论的结果进行比较，我们研究了如何确定需要描述像 HOONO 这样含有多个大振幅运动的分子的振动光谱的降维系统的大小的问题。
