Materials Data on MgCu2GeS4 by Materials Project
Cu2MgGeS4 is Stannite-like structured and crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. Mg2+ is bonded to four S2- atoms to form MgS4 tetrahedra that share corners with four equivalent GeS4 tetrahedra and corners with eight equivalent CuS4 tetrahedra. There are a spread of Mg–S bond distances ranging from 2.45–2.48 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with four equivalent MgS4 tetrahedra, corners with four equivalent CuS4 tetrahedra, and corners with four equivalent GeS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.30–2.33 Å. Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share corners with four equivalent MgS4 tetrahedra and corners with eight equivalent CuS4 tetrahedra. All Ge–S bond lengths are 2.27 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to one Mg2+, two equivalent Cu1+, and one Ge4+ atom to form corner-sharing SMgCu2Ge tetrahedra. In the second S2- site, S2- is bonded to one Mg2+, two equivalent Cu1+, and one Ge4+ atom to form corner-sharing SMgCu2Ge tetrahedra. In the third S2- site, S2- is bonded to one Mg2+, two equivalent Cu1+, and one Ge4+ atom to form corner-sharing SMgCu2Ge tetrahedra.