论文标题
$ a^3σ^+$电子状态中NALI分子的从头算属性
Ab initio properties of the NaLi molecule in the $a^3Σ^+$ electronic state
论文作者
论文摘要
最近在最低的三胞胎$ a^3σ^+$电子状态下，超速极性和磁性$ {}^{23} $ na $ {}^6 $ li分子以最低的振动基态状态。在这里，我们使用量子化学的最先进的方法来计算这些14电子分子的电子和摇摆结构。我们采用了耦合群集波函数的层次结构，高斯基集设置被推断到完整的基集限制。我们表明，对于碱金属系统的准确散射和光谱特性是必要的，包括高级激发，核心电子相关性，相对论，QED和绝热是必要的。我们获得井深，$ d_e = 229.9（5）\，$ cm $^{ - 1} $，解离能，$ d_0 = 208.2（5）\，$ cm $ $^{ - 1} $，散射长度和$ a_s = -84^+25} {+25} _ {+25} _ {+25} _ { - 41 { - 41}我们预测在Rovibrational基态处的永久性电偶极矩，$ d_0 = $ 0.167（1）$ \，$ debye。这些值是在没有对实验数据的任何调整的情况下获得的，这表明量子化学方法能够预测许多电子系统的散射特性，从而提供了相对较弱的相互作用和较小的系统质量。
Ultracold polar and magnetic ${}^{23}$Na${}^6$Li molecules in the rovibrational ground state of the lowest triplet $a^3Σ^+$ electronic state have been recently produced. Here, we calculate the electronic and rovibrational structure of these 14-electron molecules with spectroscopic accuracy ($<0.5\,$cm$^{-1}$) using state-of-the-art ab initio methods of quantum chemistry. We employ the hierarchy of the coupled-cluster wave functions and Gaussian basis sets extrapolated to the complete basis set limit. We show that the inclusion of higher-level excitations, core-electron correlation, relativistic, QED, and adiabatic corrections is necessary to reproduce accurately scattering and spectroscopic properties of alkali-metal systems. We obtain the well depth, $D_e=229.9(5)\,$cm$^{-1}$, the dissociation energy, $D_0=208.2(5)\,$cm$^{-1}$, and the scattering length, $a_s=-84^{+25}_{-41}\,$bohr, in good agreement with recent experimental measurements. We predict the permanent electric dipole moment in the rovibrational ground state, $d_0=$0.167(1)$\,$debye. These values are obtained without any adjustment to experimental data, showing that quantum chemistry methods are capable of predicting scattering properties of many-electron systems, provided relatively weak interaction and small reduced mass of the system.
