CHEMFELLS IV will make it possible to carry out research projects that were positively evaluated by the European Commission in the Horizon 2020 call, Marie Skłodowska-Curie Actions 2019 (MSCA — Individual Fellowship — European Fellowship) but could not be supported due to lack of funding. The aim of this project is to implement two key activities: the arrival of 9 researchers coming from abroad to VŠCHT Prague and the departure of one VŠCHT Prague employee to a foreign institution.