GeSi7 is Moissanite 9R-like structured and crystallizes in the cubic P-43m space group. Ge(1) is bonded to four equivalent Si(1) atoms to form GeSi4 tetrahedra that share corners with twelve equivalent Si(2)Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one Ge(1) and three equivalent Si(2) atoms to form corner-sharing SiSi3Ge tetrahedra. In the second Si site, Si(2) is bonded to four equivalent Si(1) atoms to form SiSi4 tetrahedra that share corners with four equivalent Ge(1)Si4 tetrahedra and corners with eight equivalent Si(2)Si4 tetrahedra.
GeSi7 is Moissanite 9R-like structured and crystallizes in the cubic P-43m space group. Ge(1) is bonded to four equivalent Si(1) atoms to form GeSi4 tetrahedra that share corners with twelve equivalent Si(2)Si4 tetrahedra. All Ge(1)-Si(1) bond lengths are 2.39 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one Ge(1) and three equivalent Si(2) atoms to form corner-sharing SiSi3Ge tetrahedra. All Si(1)-Si(2) bond lengths are 2.36 Å. In the second Si site, Si(2) is bonded to four equivalent Si(1) atoms to form SiSi4 tetrahedra that share corners with four equivalent Ge(1)Si4 tetrahedra and corners with eight equivalent Si(2)Si4 tetrahedra.