Na4PtPdH4 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to four equivalent Pd(1), one H(1), and four equivalent H(2) atoms to form distorted NaH5Pd4 square pyramids that share corners with eight equivalent H(2)Na5Pd octahedra, corners with four equivalent Na(1)H5Pd4 square pyramids, edges with four equivalent Na(2)H5 square pyramids, edges with eight equivalent Na(1)H5Pd4 square pyramids, and faces with five equivalent Na(1)H5Pd4 square pyramids. The corner-sharing octahedral tilt angles range from 59-121°. In the second Na site, Na(2) is bonded to one H(2) and four equivalent H(1) atoms to form distorted NaH5 square pyramids that share corners with four equivalent Na(2)H5 square pyramids, edges with four equivalent Na(2)H5 square pyramids, and edges with four equivalent Na(1)H5Pd4 square pyramids. Pt(1) is bonded in a linear geometry to two equivalent H(1) atoms. Pd(1) is bonded in a distorted linear geometry to eight equivalent Na(1) and two equivalent H(2) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded to one Na(1), four equivalent Na(2), and one Pt(1) atom to form HNa5Pt octahedra that share corners with five equivalent H(1)Na5Pt octahedra, edges with four equivalent H(2)Na5Pd octahedra, and edges with four equivalent H(1)Na5Pt octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the second H site, H(2) is bonded to one Na(2), four equivalent Na(1), and one Pd(1) atom to form HNa5Pd octahedra that share corners with five equivalent H(2)Na5Pd octahedra, corners with eight equivalent Na(1)H5Pd4 square pyramids, edges with four equivalent H(2)Na5Pd octahedra, and edges with four equivalent H(1)Na5Pt octahedra. The corner-sharing octahedral tilt angles range from 0-6°.
Na4PtPdH4 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to four equivalent Pd(1), one H(1), and four equivalent H(2) atoms to form distorted NaH5Pd4 square pyramids that share corners with eight equivalent H(2)Na5Pd octahedra, corners with four equivalent Na(1)H5Pd4 square pyramids, edges with four equivalent Na(2)H5 square pyramids, edges with eight equivalent Na(1)H5Pd4 square pyramids, and faces with five equivalent Na(1)H5Pd4 square pyramids. The corner-sharing octahedral tilt angles range from 59-121°. All Na(1)-Pd(1) bond lengths are 3.01 Å. The Na(1)-H(1) bond length is 2.40 Å. All Na(1)-H(2) bond lengths are 2.58 Å. In the second Na site, Na(2) is bonded to one H(2) and four equivalent H(1) atoms to form distorted NaH5 square pyramids that share corners with four equivalent Na(2)H5 square pyramids, edges with four equivalent Na(2)H5 square pyramids, and edges with four equivalent Na(1)H5Pd4 square pyramids. The Na(2)-H(2) bond length is 2.42 Å. All Na(2)-H(1) bond lengths are 2.58 Å. Pt(1) is bonded in a linear geometry to two equivalent H(1) atoms. Both Pt(1)-H(1) bond lengths are 1.67 Å. Pd(1) is bonded in a distorted linear geometry to eight equivalent Na(1) and two equivalent H(2) atoms. Both Pd(1)-H(2) bond lengths are 1.70 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded to one Na(1), four equivalent Na(2), and one Pt(1) atom to form HNa5Pt octahedra that share corners with five equivalent H(1)Na5Pt octahedra, edges with four equivalent H(2)Na5Pd octahedra, and edges with four equivalent H(1)Na5Pt octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the second H site, H(2) is bonded to one Na(2), four equivalent Na(1), and one Pd(1) atom to form HNa5Pd octahedra that share corners with five equivalent H(2)Na5Pd octahedra, corners with eight equivalent Na(1)H5Pd4 square pyramids, edges with four equivalent H(2)Na5Pd octahedra, and edges with four equivalent H(1)Na5Pt octahedra. The corner-sharing octahedral tilt angles range from 0-6°.