Effect of the variation of electric-dipole moments on the shape of pressure-broadened atomic spectral lines

We derive a classical path expression for a pressure-broadened atomic spect ral line shape that allows for an electric-dipole moment that is dependent on the position of perturbers. The theory is applied to the atomic hydrogen Lyman-alpha and Lyman-beta lines broadened by collisions with neutral and ionized atomic hydrogen. The far wings of the Lyman series lines exhibit sa tellites, enhancements that may be associated with quasimolecular states of H-2 and H-2(+). The sizes of these features depend on the values of the el ectric-dipole moments at the internuclear separations responsible for the s atellites. Profiles are computed with and without spatial dependence of the dipole moment, and are compared with astronomical and laboratory observati ons. We conclude that in the present case the variation of the dipole momen t is an important factor that cannot be neglected. [S1050-2947(99)10308-1].