Comment on Surface Crystal-Field Effects in the Photoemission of Xe

Recently Waclawski and Herbst reported, in the photoemission spectrum of Xe, the splitting of the $P_{\frac{3}{2}}$ level of Xe adsorbed on the (100) surface of tungsten. The observed splitting was interpreted as being the consequence of the surface crystal field. Several inconsistencies in their model are pointed out and it is shown that the splitting may be accounted for, predominantly, by the induced image field of the final-state ion. An experimental test is suggested which would help remove the ambiguity.