标题： DPF分析为Li$_2(a\,^3Σ^+_u)$和Li$_2(1\,^3 Σ^+_g)$提供了准确的解析势能，这些势能包含了在$1\,^3 Σ^+_g$-态渐近线附近的三态混合。 显示英文标题

标题： A DPF analysis yields accurate analytic potentials for Li$_2(a\,^3Σ^+_u)$ and Li$_2(1\,^3 Σ^+_g)$ that incorporate 3-state mixing near the $1\,^3 Σ^+_g$-state asymptote

摘要： 对Li$_2$的$a\,^{3}\Sigma_u^+$和$1\,^3\Sigma_g^+$状态的光学和光缔合光谱数据进行组合同位素直接势拟合（DPF）分析，为这两个状态提供了精确的解析势能函数。 推荐的M3LR$_{5,3}^{8.0}(3)$势能用于$a\,^3\Sigma_u^+$的$^{7,7}$Li$_2$具有深度为$\,{\mathfrak D}_e= 333.758(7)\,{\rm cm^{-1}}$和平衡距离为$\,r_e= 4.17005(3)~$\AA ，相关的散射长度为$\,a_{\rm SL}= -14.759(9)\,$\AA 对于$^{7,7}$Li$_2$和$-1906(50)\,$\AA 对于$^{6,6}$Li$_2$。 对于$1\,^3\Sigma_g^+$状态，尽管存在一个从$\,v(1\,^3\Sigma_g^+)= 8-61$开始的$\,\sim 5200\,{\rm cm}^{-1}$的数据缺失区间，DPF 过程在确定准确的整体势能方面没有困难。 的 $1\,^3\Sigma_g^+$ 状态的 $^{7,7}$Li$_2$ 同位素具有 $\,{\mathfrak D}_e= 7092.417(33)\,{\rm cm^{-1}}$ 的深度和 $\,r_e= 3.06524(9)~$\AA 的平衡距离。 推荐的M3LR$_{6,3}^{3.6}(9)$势能函数的长程尾部对于$1\,^3\Sigma_g^+$状态由一个$3\times 3$长程态间耦合矩阵的最低本征值定义，以考虑其渐近区域附近的三态混合。 显示英文摘要

摘要： A combined-isotopologue direct-potential-fit (DPF) analysis of optical and photoassociation spectroscopy data for the $a\,^{3}\Sigma_u^+$ and $1\,^3\Sigma_g^+$ states of Li$_2$ has yielded accurate analytic potential energy functions for both states. The recommended M3LR$_{5,3}^{8.0}(3)$ potential for the $a\,^3\Sigma_u^+$ of $^{7,7}$Li$_2$ has a well depth of $\,{\mathfrak D}_e= 333.758(7)\,{\rm cm^{-1}}$ and equilibrium distance of $\,r_e= 4.17005(3)~$\AA, and the associated scattering lengths are $\,a_{\rm SL}= -14.759(9)\,$\AA\ for $^{7,7}$Li$_2$ and $-1906(50)\,$\AA\ for $^{6,6}$Li$_2$. For the $1\,^3\Sigma_g^+$ state, in spite of a gap of $\,\sim 5200\,{\rm cm}^{-1}$ (from $\,v(1\,^3\Sigma_g^+)= 8-61$) for which there are no data, the DPF procedure has no difficulty determining an accurate overall potential. The $1\,^3\Sigma_g^+$ state of the $^{7,7}$Li$_2$ isotopologue has a well depth of $\,{\mathfrak D}_e= 7092.417(33)\,{\rm cm^{-1}}$ and equilibrium distance of $\,r_e= 3.06524(9)~$\AA. The long-range tail of the recommended M3LR$_{6,3}^{3.6}(9)$ potential energy function for the $1\,^3\Sigma_g^+$ state is defined by the lowest eigenvalue of a $3\times 3$ long-range interstate coupling matrix to take into account the 3-state mixing near its asymptote.