The Xe 5s photoelectron spectrum and 5p(4)nl correlation satellites have been studied in small Xe clusters of an average size of about 15 atoms. The satellite structures are interpreted with the help of the atomic Xe lines. Transition energy shifts between the atomic and the corner/edge/face/bulk components in clusters are divided into polarization screening and exchange interaction energy. Interestingly enough, the ratios between corner/edge/face/bulk polarization screening and exchange interaction energies are found to reflect the ratios of the coordination numbers of corner/edge/face/bulk atoms in these small icosahedral cluster structures.