Perry Adam J, Hodges James N, Markus Charles R, Kocheril G Stephen, McCall Benjamin J
Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA.
J Chem Phys. 2014 Sep 14;141(10):101101. doi: 10.1063/1.4895505.
The hydrohelium cation, HeH(+), serves as an important benchmark for ab initio calculations that take into account non-adiabatic, relativistic, and quantum electrodynamic effects. Such calculations are capable of predicting molecular transitions to an accuracy of ~300 MHz or less. However, in order to continue to push the boundaries on these calculations, new measurements of these transitions are required. Here we measure seven rovibrational transitions in the fundamental vibrational band to a precision of ~1 MHz using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy. These newly measured transitions are included in a fit to the rotation-vibration term values to derive refined spectroscopic constants in the v = 0 and v = 1 vibrational states, as well as to calculate rotation-vibration energy levels with high precision.
氢氦阳离子HeH⁺是考虑非绝热、相对论和量子电动力学效应的从头算的重要基准。此类计算能够将分子跃迁预测到约300兆赫兹或更低的精度。然而，为了继续拓展这些计算的边界，需要对这些跃迁进行新的测量。在此，我们使用抗噪声腔增强光学外差速度调制光谱技术，将基频振动带中的七个振转跃迁测量到约1兆赫兹的精度。这些新测量的跃迁被纳入对转动-振动项值的拟合中，以推导出v = 0和v = 1振动状态下的精细光谱常数，并高精度计算转动-振动能级。
