Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
J Chem Phys. 2013 Nov 28;139(20):204105. doi: 10.1063/1.4834596.
Very accurate non-Born-Oppenheimer quantum-mechanical calculations are performed to determine the average values of the interparticle distances and the proton-deuteron density function for the rovibrationally excited HD(+) ion. The states corresponding to excitations to all bound vibrational states (v = 0, ..., 22) and simultaneously excited to the first excited rotational state (N = 1) are considered. To describe each state up to 8000 explicitly correlated all-particle Gaussian functions are used. The nonlinear parameters of the Gaussians are variationally optimized using a procedure that employs the analytical energy gradient determined with respect to these parameters. The results show an increasing asymmetry in the electron distribution with the vibrational excitation as the electron density shifts towards deuteron and away from the proton.
非常精确的非玻恩-奥本海默量子力学计算被执行，以确定 rovibrationally 激发的 HD(+)离子的粒子间距离和质子-氘核密度函数的平均值。考虑了对应于所有束缚振动状态（v = 0，...，22）激发的状态，以及同时激发到第一激发转动状态（N = 1）的状态。为了描述每个状态，使用了多达 8000 个显式相关的全粒子高斯函数。使用一种程序对高斯的非线性参数进行变分优化，该程序使用相对于这些参数确定的解析能量梯度。结果表明，随着振动激发，电子分布的不对称性增加，电子密度向氘核转移，远离质子。
