Sr2Si is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Si(1) atoms. In the second Sr site, Sr(2) is bonded to four equivalent Si(1) atoms to form a mixture of corner and edge-sharing SrSi4 tetrahedra. Si(1) is bonded in a 7-coordinate geometry to three equivalent Sr(1) and four equivalent Sr(2) atoms.
Sr2Si is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Si(1) atoms. There is one shorter (3.26 Å) and two longer (3.46 Å) Sr(1)-Si(1) bond lengths. In the second Sr site, Sr(2) is bonded to four equivalent Si(1) atoms to form a mixture of corner and edge-sharing SrSi4 tetrahedra. There are a spread of Sr(2)-Si(1) bond distances ranging from 3.18-3.24 Å. Si(1) is bonded in a 7-coordinate geometry to three equivalent Sr(1) and four equivalent Sr(2) atoms.