Vacuum ultraviolet spectroscopy of deep lying impurity states in solid CF₄

We have utilized solid carbontetrafluoride as a transparant inert matrix for vacuum ultraviolet spectroscopic studies of impurity states of xenon, methyl iodide and acetylene (in the range 2000-1100 Å). n=2 and n=3 Wannier states have been observed leading to quantitative information concerning the conduction band of solid CF₄. Large blue shifts of the intermediate excited states can be rationalized in terms of central cell corrections to the n=1 Wannier state.