On description of nuclear and atomic extended states

In this report one discusses various types of spatial extended nuclear and atomic states: nuclear halo states, Coulomb and kinematical threshold states, vibrational states involved in fission phenomena and atomic Rydberg states. These states are related to non-polarizing peripheral interactions (acting outside of a core). In the present approach for a spatial extended state, the (inner space) core is represented by R-matrix while the peripheral region and the phenomena occurring there are represented by logarithmic derivative of a single channel reaction model. (authors)