  Electronic excitations and optical spectra of $CdF_{2}$ are calculated up to
ultraviolet employing state-of-the-art techniques based on density functional
theory and many-body perturbation theory. The GW scheme proposed by Hedin has
been used for the electronic self-energy to calculate single-particle
excitation properties as energy bands and densities of states. For optical
properties many-body effects, treated within the Bethe-Salpeter equation
framework, turn out to be crucial. A bound exciton located about 1 eV below the
quasiparticle gap is predicted. Within the present scheme the optical
absorption spectra and other optical functions show an excellent agreement with
experimental data. Moreover, we tested different schemes to obtain the best
agreement with experimental data. Among the several schemes, we suggest a
self-consistent quasiparticle energy scheme.
