Potential energy surfaces of the electronic states of Li2F and Li2F−

Abstract

The potential energy surfaces of the ground and low-lying excited states for the insertion reaction of atomic fluorine (F) and fluoride (F(-)) into the dilithium (Li2) molecule have been investigated. We have carried out explicitly correlated multi-reference configuration interaction (MRCI-F12) calculations using Dunning's augmented correlation-consistent basis sets. For the neutral system, the insertion of F into Li2 proceeds via a harpoon-type mechanism on the ground state surface, involving a covalent state and an ionic state which avoid each other at long distance. A detailed analysis of the changes in the dipole moment along the reaction coordinate reveals multiple avoided crossings among the excited states and shows that the charge-transfer processes play a pivotal role for the stabilization of the low-lying electronic states of Li2F. For the anionic system, which is studied for the first time, the insertion of F(-) is barrierless for many states and there is a gradual charge transfer from F(-) to Li2 along the reaction path. We also report the optimized parameters and the spectroscopic properties of the five lowest states of the neutral and seven lowest states of the anionic systems, which are strongly stabilized with respect to their respective Li2 + F/F(-) asymptotes. The observed barrierless insertion mechanisms for both systems make them good candidates for investigation under the ultracold regime.

Lowest electronic states of neutral and ionic LiN

“…In contrast, for the bound 2 3 ∑ − state, there is a charge transfer from the N atom to the Li atom, initiated around 3.0 Å. One should note that the effective charge model at shorter distances ( R ≤ 2.0 Å) is not valid since the center of positive or negative charges is not well defined [38].…”

The Ground-State Potential Energy Surface of F-Li2 Polymer

“…In recent years, Lithium is found to be form stoichiometric polymer with various elements. On the other hand, There are a lot of practical application of fluoride, such as the six lithium fluoride phosphate is the core of the electrolyte materials, and is one of the key materials necessary for the lithium battery electrolyte; LiF and other electronic injection material introduction of organic optoelectronic devices have become a good luminescent material [1][2][3][4]. F-Li 2 Polymer belongs to super valence compounds containing odd electronic, it has good nonlinear optical properties, so the scientists study on super molecular structure of alkali metal fluoride has always maintained a strong interesting in F-Li 2 [5][6][7].…”