We present self-consistent field Hartree-Fock calculations of the excitonic fine structure of the arsenic K-edge for several arsenic fluorine cage molecules AsFn(n = 3, 5, 6). Ground-state energies and K-shell ionization energies are computed. The binding energies relative to the K-shell ionization energy of several excitonic states, made up of a 1s core hole and an electron in a valence or Rydberg final state, are found. The relative oscillato, strengths for X-ray absorption to these states are determined and good agreement with experimental X-ray absorption data on AsF5 in the gas phase is found. © 1984.