New observation of the , 13Δg, and 23Πg states and molecular constants with all 6Li2, 7Li2, and 6Li7Li data

Spectroscopy of Lithium Atoms and Molecules on Helium Nanodroplets

“…This is a valid approach within the Born−Oppenheimer approximation, where the three Li 2 isotopomers have identical potential curves. Although Born−Oppenheimer breakdown effects are significant in Li 2 ,61 they can be neglected within the accuracy of our results. A direct determination of T e from our data is not possible since we only have access to the triplet molecule.…”

“…Therefore, we determine the molecular constants for the sake of comparison with the literature values of free molecules. In Table , we summarize the molecular constants as obtained from a least-squares fit of the observed band positions to the standard expression The obtained results are compared to experimental results from Xie and Field (for 6 Li 2 ) and Li et al (for 7 Li 2 ). The parameters for 6 Li 7 Li are calculated from the 7 Li 2 parameter by a multiplication with the isotope factor ρ = (μ 7 /μ) 1/2 , where μ 7 and μ are the reduced masses of 7 Li 2 and 6 Li 7 Li, respectively.…”

“…Parameters are given in cm −1 , and one standard deviation uncertainties are given in parentheses. Parameters for 6 Li 7 Li are calculated from the parameters given by Li et al 61 The Experimental high resolution data and theoretical calculations are available for the 2 3 Π g state. This allows a detailed comparison between the spectroscopy of free molecules and molecules on the droplet.…”

Analytic potentials and vibrational energies for Li$_{2}$ states dissociating to $\mbox{Li}\left(2S\right)+\mbox{Li}\left(3P\right)$. Part 1: The $^{2S+1}Π_{u/g}$ states

“…Out of the first 5 asymptotes (from lowest to highest: 2S + 2S, 2S + 2P , 2S+3S, 2P +2P and 2S+3P ), the 2S+3P is the only one for which an empirical dissociation energy has not been determined for any of the electronic states dissociating to it. Furthermore, the only measurements that have been made for electronic states dissociating to 2S + 3P , were for the 3c(3 3 Σ + g ) state [1][2][3] the 6X(6 1 Σ + g ) state [4,5], and the 3d(3 3 Π g ) state [6][7][8][9]. No measurements have been done on the other states dissociating to 2S + 3P .…”

State of the art for ab initio vs empirical potentials for predicting 6e$^{-}$ excited state molecular energies: Application to Li$_{2}\left(b,1^{3}Π_{u}\right)$

“…Finally, the b(1 3 Π u )-state has been a key doorway to the triplet manifold, and was directly involved in the measurements for a vast number of other triplet states such as 2 3 ∆ g [6], 3 3 Π g [7], 3 3 Σ + g [7][8][9], 2 3 Σ + g [7,10], 2 3 Π g [7][8][9]11], 1 3 ∆ g [8,9,[11][12][13][14], 1 3 Σ − g , and other undetermined 3 Λ states [15,16]. Some of these more highly excited triplet states (namely 3 3 Σ + g , 2 3 Σ + g , 2 3 Π g , and 1 3 ∆ g ) are so thoroughly covered by these spectroscopic measurements, that global empirical potentials can be built for them too.…”