Sr(YSe2)2 crystallizes in the orthorhombic Pnma space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one Se(3), two equivalent Se(1), and three equivalent Se(4) atoms to form a mixture of corner and edge-sharing YSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-63°. In the second Y site, Y(2) is bonded to one Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of corner and edge-sharing YSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-63°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Sr(1), one Y(2), and two equivalent Y(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Y3 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent Sr(1) and three equivalent Y(2) atoms to form a mixture of corner and edge-sharing SeSr2Y3 square pyramids. In the third Se site, Se(3) is bonded to two equivalent Sr(1), one Y(1), and two equivalent Y(2) atoms to form a mixture of distorted corner and edge-sharing SeSr2Y3 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to two equivalent Sr(1) and three equivalent Y(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Y3 trigonal bipyramids.
Sr(YSe2)2 crystallizes in the orthorhombic Pnma space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. Both Sr(1)-Se(1) bond lengths are 3.23 Å. Both Sr(1)-Se(2) bond lengths are 3.21 Å. There is one shorter (3.41 Å) and one longer (3.49 Å) Sr(1)-Se(3) bond length. Both Sr(1)-Se(4) bond lengths are 3.25 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one Se(3), two equivalent Se(1), and three equivalent Se(4) atoms to form a mixture of corner and edge-sharing YSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-63°. The Y(1)-Se(3) bond length is 2.83 Å. Both Y(1)-Se(1) bond lengths are 2.89 Å. There is one shorter (2.84 Å) and two longer (2.87 Å) Y(1)-Se(4) bond lengths. In the second Y site, Y(2) is bonded to one Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of corner and edge-sharing YSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-63°. The Y(2)-Se(1) bond length is 2.89 Å. Both Y(2)-Se(3) bond lengths are 2.81 Å. There is one shorter (2.87 Å) and two longer (2.88 Å) Y(2)-Se(2) bond lengths. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Sr(1), one Y(2), and two equivalent Y(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Y3 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent Sr(1) and three equivalent Y(2) atoms to form a mixture of corner and edge-sharing SeSr2Y3 square pyramids. In the third Se site, Se(3) is bonded to two equivalent Sr(1), one Y(1), and two equivalent Y(2) atoms to form a mixture of distorted corner and edge-sharing SeSr2Y3 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to two equivalent Sr(1) and three equivalent Y(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Y3 trigonal bipyramids.