Abstract EuH2 was synthesized from the elements. The phase boundary EuHx. between europium and europium dihydride (nonstoichiometric) was found at x = 1.8. Spark source mass spectrographic analysis of EuH1.90 ± 0.02 gave a total amount of impurities of 511 ppm. Europium dihydride does not react further under pressures up to 400 atm at 400 °C. The densitometrically determined X-ray intensities allowed calculation of the structural parameters of the Eu ions in the metal sublattice. The space group of this orthorhombic structure is Pnma (No. 62). Europium was found in the 4c position with x = 0.240, y = 1 4 , z = 0.110. The structure as well as the possible position of the hydrogen ions is discussed. The implications for the magnetic properties (unexpectedly low or high ferromagnetic Curie temperature) are shown. A possible term scheme of the 5d-orbitals is discussed which shows that the lower part of the expected 5d-band is formed by t2g and eg contributions. An extension of this interpretation leads to a prediction of the magnetic properties of EuF2.