An ab initio molecular orbital study of the electronic spectrum and dissociation features of Li2F Original Research Article

Ab initio electronic structure calculations have been used to determine spectroscopic constants and bonding features of the best stable triangular and linear conformations of Li2F. Bonding populations show that the ionic valence bond structure F− Li2+ is responsible for the ground state X 2A1 and the first excited state 1 2Σ+u. The electronic spectrum of Li2F has been predicted by MRD–CI calculations. The strongest band corresponding to the first excitation of 1 2B2–X 2A1 centers at 1.2361 eV. Broadside dissociation behavior of Li2F has been investigated by combining CASSCF and VBSCF calculations. A nonadiabatic electron transfer process during the broadside dissociation process was predicted to take place at the Li–F distance of 3.7 Å.