Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
Phys Chem Chem Phys. 2010 Aug 1;12(29):8387-97. doi: 10.1039/c002803g. Epub 2010 Jun 5.
Rotation-torsion spectra of HSOH, involving the vibrational ground state and the fundamental torsional state, have been simulated at T = 300 K. The simulations are carried out with the variational computer program TROVE in conjunction with recently reported ab initio potential energy and electric dipole moment surfaces. HSOH is a near-prolate-symmetric top at equilibrium and the simulated spectra are of perpendicular-band-type with strong R-branch and Q-branch transitions. Recently, an anomalous (b-type-transition)/(c-type-transition) intensity ratio in the vibrational-ground-state (r)Q(K(a))-branches of HSOH has been experimentally observed. Our calculations reproduce correctly the anomaly and show that it originates in the large-amplitude torsional motion of HSOH. We analyze our theoretical results in order to explain the effect and to provide unambiguous (b/c)-type-transition assignments.
在 T = 300 K 下，模拟了涉及振动基态和基本扭转态的 HSOH 的扭转-旋转光谱。这些模拟是使用变分计算机程序 TROVE 与最近报道的从头算势能和电偶极矩表面结合进行的。HSOH 在平衡时是一个近扁长对称陀螺，模拟的光谱是垂直带型的，具有强 R 支和 Q 支跃迁。最近，在 HSOH 的振动基态（r）Q（K（a））支中实验观察到了异常的（b 型跃迁）/（c 型跃迁）强度比。我们的计算正确地再现了这种异常，并表明它源于 HSOH 的大幅度扭转运动。我们分析了我们的理论结果，以解释这种效应，并提供明确的（b/c）-型跃迁分配。
