Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA.
J Chem Phys. 2014 Mar 28;140(12):124315. doi: 10.1063/1.4869517.
Very accurate calculations of the ground-state potential energy curve (PEC) of the LiH(+) ion performed with all-electron explicitly correlated Gaussian functions with shifted centers are presented. The variational method is employed. The calculations involve optimization of nonlinear exponential parameters of the Gaussians performed with the aid of the analytical first derivatives of the energy determined with respect to the parameters. The diagonal adiabatic correction is also calculated for each PEC point. The PEC is then used to calculate the vibrational energies of the system. In that calculation, the non-adiabatic effects are accounted for by using an effective vibrational mass obtained by the minimization of the difference between the vibrational energies obtained from the calculations where the Born-Oppenheimer approximation was not assumed and the results of the present calculations.
我们用带移动中心的完全电子关联高斯函数，对 LiH(+) 离子的基态势能曲线（PEC）进行了非常精确的计算。采用变分法。计算涉及用能量相对于参数的解析一阶导数来辅助优化高斯函数的非线性指数参数。还为每个 PEC 点计算了对角绝热修正。然后使用 PEC 来计算系统的振动能。在该计算中，通过最小化从不假设玻恩-奥本海默近似的计算中获得的振动能与本计算结果之间的差异来获得有效振动质量，从而考虑了非绝热效应。
