La2H5 crystallizes in the tetragonal I4_1md space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a distorted body-centered cubic geometry to three equivalent H(2) and eight equivalent H(1) atoms. In the second La site, La(2) 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 two equivalent La(1) and two equivalent La(2) 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 52-59°. In the second H site, H(2) is bonded to three equivalent La(1) and three equivalent La(2) 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 range from 1-4°.
La2H5 crystallizes in the tetragonal I4_1md space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a distorted body-centered cubic geometry to three equivalent H(2) and eight equivalent H(1) atoms. There is one shorter (2.73 Å) and two longer (2.79 Å) La(1)-H(2) bond lengths. There are four shorter (2.40 Å) and four longer (2.47 Å) La(1)-H(1) bond lengths. In the second La site, La(2) is bonded in a distorted body-centered cubic geometry to three equivalent H(2) and eight equivalent H(1) atoms. There are two shorter (2.79 Å) and one longer (2.85 Å) La(2)-H(2) bond length. There are four shorter (2.39 Å) and four longer (2.46 Å) La(2)-H(1) bond lengths. There are two inequivalent H sites. In the first H site, H(1) is bonded to two equivalent La(1) and two equivalent La(2) 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 52-59°. In the second H site, H(2) is bonded to three equivalent La(1) and three equivalent La(2) 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 range from 1-4°.