Shannon and Fisher entropies for a hydrogen atom under soft spherical confinement

We calculate Shannon and Fisher entropies in the position and momentum space, and some complexity measures for a variationally described hydrogen atom confined in soft and hard spherical boxes of varying dimension rc and selected values of strength U0. We include calculations for a free particle trapped in impenetrable boxes. It is found that the Shannon entropy Sr becomes negative for small cavity radii and large values of U0, due to the highly localized nature of the particle. For soft confinement and small cavity dimensions, the entropies change very rapidly over short radial intervals.