Materials Data on K4Zn2Sn21 by Materials Project
K4Zn2Sn21 crystallizes in the orthorhombic Ama2 space group. The structure is three-dimensional. there are four inequivalent K sites. In the first K site, K is bonded in a 8-coordinate geometry to eight Sn atoms. There are a spread of K–Sn bond distances ranging from 4.08–4.19 Å. In the second K site, K is bonded in a 8-coordinate geometry to eight Sn atoms. There are a spread of K–Sn bond distances ranging from 4.09–4.18 Å. In the third K site, K is bonded in a 8-coordinate geometry to eight Sn atoms. There are a spread of K–Sn bond distances ranging from 4.08–4.18 Å. In the fourth K site, K is bonded in a 12-coordinate geometry to twelve Sn atoms. There are a spread of K–Sn bond distances ranging from 3.86–4.05 Å. There are two inequivalent Zn sites. In the first Zn site, Zn is bonded to four Sn atoms to form ZnSn4 tetrahedra that share corners with eight SnKSn4 trigonal bipyramids. There are two shorter (2.77 Å) and two longer (2.78 Å) Zn–Sn bond lengths. In the second Zn site, Zn is bonded to four Sn atoms to form ZnSn4 tetrahedra that share corners with eight SnKSn4 trigonal bipyramids. There are one shorter (2.72 Å) and three longer (2.73 Å) Zn–Sn bond lengths. There are thirteen inequivalent Sn sites. In the first Sn site, Sn is bonded to four Sn atoms to form corner-sharing SnSn4 tetrahedra. There are one shorter (2.93 Å) and three longer (2.94 Å) Sn–Sn bond lengths. In the second Sn site, Sn is bonded in a distorted single-bond geometry to two K, one Zn, and two Sn atoms. Both Sn–Sn bond lengths are 2.87 Å. In the third Sn site, Sn is bonded in a 4-coordinate geometry to three K and four Sn atoms. There are a spread of Sn–Sn bond distances ranging from 2.86–2.96 Å. In the fourth Sn site, Sn is bonded in a 4-coordinate geometry to three K and four Sn atoms. There are two shorter (2.86 Å) and one longer (2.95 Å) Sn–Sn bond lengths. In the fifth Sn site, Sn is bonded in a distorted single-bond geometry to two K, one Zn, and two Sn atoms. Both Sn–Sn bond lengths are 2.88 Å. In the sixth Sn site, Sn is bonded in a distorted single-bond geometry to two K, one Zn, and three Sn atoms. Both Sn–Sn bond lengths are 2.88 Å. In the seventh Sn site, Sn is bonded in a distorted single-bond geometry to two equivalent K, one Zn, and three Sn atoms. There are two shorter (2.89 Å) and one longer (2.96 Å) Sn–Sn bond lengths. In the eighth Sn site, Sn is bonded in a distorted single-bond geometry to two equivalent K, one Zn, and three Sn atoms. Both Sn–Sn bond lengths are 2.88 Å. In the ninth Sn site, Sn is bonded in a 4-coordinate geometry to three K and four Sn atoms. Both Sn–Sn bond lengths are 2.87 Å. In the tenth Sn site, Sn is bonded to one K and four Sn atoms to form distorted SnKSn4 trigonal bipyramids that share a cornercorner with one ZnSn4 tetrahedra, corners with two equivalent SnSn4 tetrahedra, corners with four SnKSn4 trigonal bipyramids, and edges with three SnKSn4 trigonal bipyramids. The Sn–Sn bond length is 2.88 Å. In the eleventh Sn site, Sn is bonded to one K and four Sn atoms to form distorted SnKSn4 trigonal bipyramids that share corners with three ZnSn4 tetrahedra, corners with four SnKSn4 trigonal bipyramids, and edges with three SnKSn4 trigonal bipyramids. The Sn–Sn bond length is 2.93 Å. In the twelfth Sn site, Sn is bonded to one K and four Sn atoms to form distorted SnKSn4 trigonal bipyramids that share a cornercorner with one SnSn4 tetrahedra, corners with two ZnSn4 tetrahedra, corners with four SnKSn4 trigonal bipyramids, and edges with three SnKSn4 trigonal bipyramids. The Sn–Sn bond length is 2.90 Å. In the thirteenth Sn site, Sn is bonded to one K and four Sn atoms to form distorted SnKSn4 trigonal bipyramids that share a cornercorner with one SnSn4 tetrahedra, corners with two ZnSn4 tetrahedra, corners with four SnKSn4 trigonal bipyramids, and edges with three SnKSn4 trigonal bipyramids.