论文标题
$ a^3σ_U^+$ lithium二聚体状态的势能曲线，带有斜方型轨道
Potential energy curve for the $a^3Σ_u^+$ state of lithium dimer with Slater-type orbitals
论文作者
论文摘要
我们报告了用于实现光谱准确性（$ <$ <$ <$ <$ 1cm $^{ - 1} $）的$ a^3σ_U^+$的势能曲线的最先进计算，而无需任何事先调整以适合相应的实验数据。相互作用能量的非层压夹具核中的成分是通过涉及六电子耦合群集和完整构型相互作用理论的复合方法计算的，结合了从双重到sextuple-Zeta的基础质量范围的基础质量范围。为了超越非依恋主义的伯彭海默氏症图片，我们既包括领先的相对论和绝热的校正，又包括在当前准确性标准中不可忽略的这两种效果。我们开发的势能曲线可以计算该系统的分子参数（$ d_e $，$ d_0 $，$ω_e$等），以及相应的振动能级，仅误差仅为vavenumber（$ 0.2-0.4 \，$ cm $ $ cm $^{ - 1} {-1} $ 0.2-0.4 \ $ 0.2-0.4 \）。我们还报告了两个$^2S $锂原子的散射长度的概念值，该原子决定了相关的Bose-Einstein冷凝水的稳定性。
We report state-of-the-art ab initio calculations of the potential energy curve for the $a^3Σ_u^+$ state of the lithium dimer conducted to achieve spectroscopic accuracy ($<$1cm$^{-1}$) without any prior adjustment to fit the corresponding experimental data. The nonrelativistic clamped-nuclei component of the interaction energy is calculated with a composite method involving six-electron coupled cluster and full configuration interaction theories combined with basis sets of Slater-type orbitals ranging in quality from double- to sextuple-zeta. To go beyond the nonrelativistic Born-Oppenheimer picture we include both the leading-order relativistic and adiabatic corrections, and find both of these effects to be non-negligible within the present accuracy standards. The potential energy curve developed by us allowed to calculate molecular parameters ($D_e$, $D_0$, $ω_e$ etc.) for this system, as well as the corresponding vibrational energy levels, with an error of only a few tenths of a wavenumber ($0.2-0.4\,$cm$^{-1}$). We also report an ab initio value for the scattering length of two $^2S$ lithium atoms which determines the stability of the related Bose-Einstein condensate.
