Scientists at the MPIK collaborate with other research groups in Europe and all over the world and are involved in numerous international collaborations, partly in a leading role. Particularly close connections to some large-scale facilities like GSI (Darmstadt), DESY (Hamburg), CERN (Geneva), TRIUMF (Canada), and INFN - LNGS (Assergi L‘Aquila) exist. The institute has about 390 employees, as well as many diploma students and scientific guests.