La2H5 crystallizes in the tetragonal I4_1/amd space group. La(1) is bonded in a distorted body-centered cubic geometry to three equivalent H(2) and eight equivalent H(1) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded to four equivalent La(1) atoms to form HLa4 tetrahedra that share corners with six equivalent H(2)La6 octahedra, corners with sixteen equivalent H(1)La4 tetrahedra, edges with six equivalent H(1)La4 tetrahedra, and faces with two equivalent H(2)La6 octahedra. The corner-sharing octahedral tilt angles range from 52-58°. In the second H site, H(2) is bonded to six equivalent La(1) atoms to form HLa6 octahedra that share corners with four equivalent H(2)La6 octahedra, corners with twenty-four equivalent H(1)La4 tetrahedra, edges with four equivalent H(2)La6 octahedra, and faces with eight equivalent H(1)La4 tetrahedra. The corner-sharing octahedral tilt angles are 2°.
La2H5 crystallizes in the tetragonal I4_1/amd space group. La(1) is bonded in a distorted body-centered cubic geometry to three equivalent H(2) and eight equivalent H(1) atoms. All La(1)-H(2) bond lengths are 2.79 Å. There are four shorter (2.40 Å) and four longer (2.47 Å) La(1)-H(1) bond lengths. There are two inequivalent H sites. In the first H site, H(1) is bonded to four equivalent La(1) atoms to form HLa4 tetrahedra that share corners with six equivalent H(2)La6 octahedra, corners with sixteen equivalent H(1)La4 tetrahedra, edges with six equivalent H(1)La4 tetrahedra, and faces with two equivalent H(2)La6 octahedra. The corner-sharing octahedral tilt angles range from 52-58°. In the second H site, H(2) is bonded to six equivalent La(1) atoms to form HLa6 octahedra that share corners with four equivalent H(2)La6 octahedra, corners with twenty-four equivalent H(1)La4 tetrahedra, edges with four equivalent H(2)La6 octahedra, and faces with eight equivalent H(1)La4 tetrahedra. The corner-sharing octahedral tilt angles are 2°.