Materials Data on Sm(SiAg)2 by Materials Project
Sm(AgSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sm3+ is bonded to eight equivalent Si4- atoms to form SmSi8 hexagonal bipyramids that share corners with sixteen equivalent AgSi4 tetrahedra, edges with four equivalent SmSi8 hexagonal bipyramids, edges with eight equivalent AgSi4 tetrahedra, and faces with four equivalent SmSi8 hexagonal bipyramids. All Sm–Si bond lengths are 3.20 Å. Ag+2.50+ is bonded to four equivalent Si4- atoms to form AgSi4 tetrahedra that share corners with eight equivalent SmSi8 hexagonal bipyramids, corners with four equivalent AgSi4 tetrahedra, edges with four equivalent SmSi8 hexagonal bipyramids, and edges with four equivalent AgSi4 tetrahedra. All Ag–Si bond lengths are 2.61 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Sm3+, four equivalent Ag+2.50+, and one Si4- atom. The Si–Si bond length is 2.31 Å.