EuH2 crystallizes in the hexagonal P6_3/mmc space group. Eu(1) is bonded in a 11-coordinate geometry to five equivalent H(1) and six equivalent H(2) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded to five equivalent Eu(1) atoms to form HEu5 trigonal bipyramids that share corners with twelve equivalent H(2)Eu6 octahedra, corners with eight equivalent H(1)Eu5 trigonal bipyramids, edges with six equivalent H(1)Eu5 trigonal bipyramids, and faces with six equivalent H(2)Eu6 octahedra. The corner-sharing octahedral tilt angles range from 31-59°. In the second H site, H(2) is bonded to six equivalent Eu(1) atoms to form HEu6 octahedra that share corners with twelve equivalent H(2)Eu6 octahedra, corners with twelve equivalent H(1)Eu5 trigonal bipyramids, edges with six equivalent H(2)Eu6 octahedra, faces with two equivalent H(2)Eu6 octahedra, and faces with six equivalent H(1)Eu5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°.
EuH2 crystallizes in the hexagonal P6_3/mmc space group. Eu(1) is bonded in a 11-coordinate geometry to five equivalent H(1) and six equivalent H(2) atoms. There are three shorter (2.31 Å) and two longer (2.74 Å) Eu(1)-H(1) bond lengths. All Eu(1)-H(2) bond lengths are 2.69 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded to five equivalent Eu(1) atoms to form HEu5 trigonal bipyramids that share corners with twelve equivalent H(2)Eu6 octahedra, corners with eight equivalent H(1)Eu5 trigonal bipyramids, edges with six equivalent H(1)Eu5 trigonal bipyramids, and faces with six equivalent H(2)Eu6 octahedra. The corner-sharing octahedral tilt angles range from 31-59°. In the second H site, H(2) is bonded to six equivalent Eu(1) atoms to form HEu6 octahedra that share corners with twelve equivalent H(2)Eu6 octahedra, corners with twelve equivalent H(1)Eu5 trigonal bipyramids, edges with six equivalent H(2)Eu6 octahedra, faces with two equivalent H(2)Eu6 octahedra, and faces with six equivalent H(1)Eu5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°.