The surface ionization method offers the possibility of measuring ionization energies of atoms, inorganic and organic molecules and clusters, In this study we report the results of the surface ionization of Li2F molecules on a rhenium surface, This work is an attempt to investigate the applicability of the surface ionization technique for the measurment of the ionization energies of hypervalent molelcules at high temperature, There are currently no reliable experimental data for the ionization energy of the Li2F molecule, This molecule has been chosen because previous theoretical calculations have shown that Li2F is a hypervalent (hyperlithiated) molecule with a low ionization energy, The ionization energy was determined to be 5.42+/-0.04 eV
