Core excitons in solid rare gases: Nonstructural theory

We study transitions from inner shells in solid rare gases using a nonstructural theory in direct space which provides the proper behavior in any intermediate situation between the effective-mass approximation (EMA) and the atomic limit. This theory has been successful in describing all the valence excitons in the whole solid-rare-gases series. We find as well that it gives a proper description of all the core excitons. First- and second-class excitons occur for the core transitions, i.e., with s- and p-type envelope functions. The latter turn out to be rather close to the EMA limit, whereas the former exhibit larger quantum defects δₙˢ and a more atomiclike behavior. The interband transition edges Egˢ, which are not directly measured, are obtained as exciton-series limits.