The free-free continuum for oxygen was earlier computed by us using wavefunctions for the free electron whose computation ignores polarization and exchange. Here these effects are included and their influence on the free-free continuum in the presence of neutral oxygen is studied. The inclusion of polarization leads to results which available experimental data tell us are a notable improvement over the earlier calculation. The inclusion of exchange is not of nearly as much consequence.
R. G. BREENE, JR. and MARIA C. NARDONE, "Free-Free Continuum of Oxygen. II. Effect of Polarization and Exchange," J. Opt. Soc. Am. 53, 924-926 (1963)