Manz Jörn, Pérez-Torres Jhon Fredy, Yang Yonggang
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University , 92 Wucheng Road, Taiyuan 030006, China.
J Phys Chem A. 2014 Sep 18;118(37):8411-25. doi: 10.1021/jp5017246. Epub 2014 May 2.
We present quantum dynamics simulations of the concerted nuclear and electronic densities and flux densities of the vibrating H2(+) ion with quantum numbers (2)Σg(+), JM = 00 corresponding to the electronic and rotational ground state, in the laboratory frame. The underlying theory is derived using the nonrelativistic and Born–Oppenheimer approximations. It is well-known that the nuclear density of the nonrotating ion (JM = 00) is isotropic. We show that the electronic density is isotropic as well, confirming intuition. As a consequence, the nuclear and electronic flux densities have radial symmetry. They are related to the corresponding densities by radial continuity equations with proper boundary conditions. The time evolutions of all four observables, i.e., the nuclear and electronic densities and flux densities, are illustrated by means of characteristic snapshots. As an example, we consider the scenario with initial condition corresponding to preparation of H2(+) by near-resonant weak field one-photon-photoionization of the H2 molecule in its ground state, (1)Σg(+), vJM = 000. Accordingly, the vibrating, nonrotating H2(+) ion appears as pulsating quantum bubble in the laboratory frame, quite different from traditional considerations of vibrating H2+ in the molecular frame, or of the familiar alternative scenario of aligned vibrating H2(+) in the laboratory frame.
我们展示了在实验室坐标系中,对具有量子数(2)Σg(+)、JM = 00(对应于电子和转动基态)的振动H2(+)离子的核密度、电子密度和通量密度进行的量子动力学模拟。基础理论是使用非相对论和玻恩-奥本海默近似推导出来的。众所周知,非旋转离子(JM = 00)的核密度是各向同性的。我们表明电子密度也是各向同性的,这证实了直觉。因此,核通量密度和电子通量密度具有径向对称性。它们通过具有适当边界条件的径向连续性方程与相应的密度相关。所有四个可观测量,即核密度、电子密度和通量密度的时间演化,通过特征快照进行了说明。作为一个例子,我们考虑初始条件对应于通过处于基态(1)Σg(+)、vJM = 000的H2分子的近共振弱场单光子光电离来制备H2(+)的情况。因此,在实验室坐标系中,振动的、非旋转的H2(+)离子表现为脉动量子泡,这与在分子坐标系中对振动H2+的传统考虑,或在实验室坐标系中对齐振动H2(+)的常见替代情况有很大不同。