Sr5Pt4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one Pt(3), two equivalent Pt(2), and three equivalent Pt(1) atoms. In the second Sr site, Sr(2) is bonded to one Pt(2), two equivalent Pt(3), and four equivalent Pt(1) atoms to form distorted SrPt7 pentagonal bipyramids that share corners with four equivalent Sr(3)Pt6 octahedra, corners with six equivalent Sr(2)Pt7 pentagonal bipyramids, edges with two equivalent Sr(2)Pt7 pentagonal bipyramids, faces with two equivalent Sr(3)Pt6 octahedra, and faces with three equivalent Sr(2)Pt7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-54°. In the third Sr site, Sr(3) is bonded to two equivalent Pt(1), two equivalent Pt(2), and two equivalent Pt(3) atoms to form distorted SrPt6 octahedra that share corners with four equivalent Sr(3)Pt6 octahedra, corners with eight equivalent Sr(2)Pt7 pentagonal bipyramids, and faces with four equivalent Sr(2)Pt7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 55°. There are three inequivalent Pt sites. In the first Pt site, Pt(3) is bonded in a 9-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), four equivalent Sr(2), and one Pt(2) atom. In the second Pt site, Pt(1) is bonded in a 9-coordinate geometry to one Sr(3), three equivalent Sr(1), four equivalent Sr(2), and one Pt(1) atom. In the third Pt site, Pt(2) is bonded in a 9-coordinate geometry to two equivalent Sr(2), two equivalent Sr(3), four equivalent Sr(1), and one Pt(3) atom.
Sr5Pt4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one Pt(3), two equivalent Pt(2), and three equivalent Pt(1) atoms. The Sr(1)-Pt(3) bond length is 3.23 Å. There is one shorter (3.12 Å) and one longer (3.21 Å) Sr(1)-Pt(2) bond length. There are a spread of Sr(1)-Pt(1) bond distances ranging from 3.03-3.10 Å. In the second Sr site, Sr(2) is bonded to one Pt(2), two equivalent Pt(3), and four equivalent Pt(1) atoms to form distorted SrPt7 pentagonal bipyramids that share corners with four equivalent Sr(3)Pt6 octahedra, corners with six equivalent Sr(2)Pt7 pentagonal bipyramids, edges with two equivalent Sr(2)Pt7 pentagonal bipyramids, faces with two equivalent Sr(3)Pt6 octahedra, and faces with three equivalent Sr(2)Pt7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-54°. The Sr(2)-Pt(2) bond length is 3.39 Å. There is one shorter (3.29 Å) and one longer (3.42 Å) Sr(2)-Pt(3) bond length. There are a spread of Sr(2)-Pt(1) bond distances ranging from 3.25-3.60 Å. In the third Sr site, Sr(3) is bonded to two equivalent Pt(1), two equivalent Pt(2), and two equivalent Pt(3) atoms to form distorted SrPt6 octahedra that share corners with four equivalent Sr(3)Pt6 octahedra, corners with eight equivalent Sr(2)Pt7 pentagonal bipyramids, and faces with four equivalent Sr(2)Pt7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 55°. Both Sr(3)-Pt(1) bond lengths are 3.33 Å. There is one shorter (3.05 Å) and one longer (3.54 Å) Sr(3)-Pt(2) bond length. There is one shorter (3.06 Å) and one longer (3.20 Å) Sr(3)-Pt(3) bond length. There are three inequivalent Pt sites. In the first Pt site, Pt(3) is bonded in a 9-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), four equivalent Sr(2), and one Pt(2) atom. The Pt(3)-Pt(2) bond length is 2.73 Å. In the second Pt site, Pt(1) is bonded in a 9-coordinate geometry to one Sr(3), three equivalent Sr(1), four equivalent Sr(2), and one Pt(1) atom. The Pt(1)-Pt(1) bond length is 2.98 Å. In the third Pt site, Pt(2) is bonded in a 9-coordinate geometry to two equivalent Sr(2), two equivalent Sr(3), four equivalent Sr(1), and one Pt(3) atom.