Structure and stability of Li2F

The equilibrium geometries and fundamental vibration frequencies of the Li2 F system were calculated by ab initio methods at the MP2 = full/6-311(+ +)G ** and CCSD(T) levels. Two isomers were observed and are best described as salts of the Li-2(+) cation with F-. A linear isomer with an arrangement of atoms such as Li-Li-F and a bent C-2v structure are predicted. The stabili ty of these structures are discussed in terms of charge resonance between L i and Li+. (C) 1999 Elsevier Science B.V. All rights reserved.