Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 6089, BP 1039, F-51687, Reims Cedex 2, France.
J Chem Phys. 2012 Jun 28;136(24):244106. doi: 10.1063/1.4730030.
A rovibrational model based on the normal-mode complete nuclear Hamiltonian is applied to methane using our recent potential energy surface [A. V. Nikitin, M. Rey, and Vl. G. Tyuterev, Chem. Phys. Lett. 501, 179 (2011)]. The kinetic energy operator and the potential energy function are expanded in power series to which a new truncation-reduction technique is applied. The vibration-rotation Hamiltonian is transformed systematically to a full symmetrized form using irreducible tensor operators. Each term of the Hamiltonian expansion can be thus cast in the tensor form whatever the order of the development. This allows to take full advantage of the symmetry properties for doubly and triply degenerate vibrations and vibration-rotation states. We apply this model to variational computations of energy levels for (12)CH(4), (13)CH(4), and (12)CD(4).
基于完整的正则模式核哈密顿量的 Rovibrational 模型被应用于甲烷，使用我们最近的势能面 [A. V. Nikitin、M. Rey 和 Vl. G. Tyuterev，Chem. Phys. Lett. 501, 179 (2011)]。动能算子和势能函数被展开为幂级数，其中应用了一种新的截断-约简技术。振动-转动哈密顿量被系统地转化为完全对称化形式，使用不可约张量算符。因此，无论展开的阶数如何，哈密顿量展开的每个项都可以表示为张量形式。这允许充分利用双简并和三重简并振动以及振动-转动态的对称性质。我们将该模型应用于 (12)CH(4)、(13)CH(4) 和 (12)CD(4) 的能级变分计算。
