DOE OSTI2020
EuZn2Ge2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Eu is bonded in a 12-coordinate geometry to eight Zn and eight Ge atoms. There are four shorter (3.32 Å) and four longer (3.43 Å) Eu–Zn bond lengths. There are four shorter (3.31 Å) and four longer (3.43 Å) Eu–Ge bond lengths. There are two inequivalent Zn sites. In the first Zn site, Zn is bonded to four equivalent Eu and four equivalent Ge atoms to form distorted ZnEu4Ge4 tetrahedra that share corners with twelve equivalent GeEu4Zn4 tetrahedra, edges with two equivalent GeEu4Zn4 tetrahedra, edges with four equivalent ZnEu4Ge4 tetrahedra, and faces with four equivalent ZnEu4Ge4 tetrahedra. All Zn–Ge bond lengths are 2.60 Å. In the second Zn site, Zn is bonded in a 5-coordinate geometry to four equivalent Eu and five Ge atoms. There are one shorter (2.45 Å) and four longer (2.59 Å) Zn–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded to four equivalent Eu and four equivalent Zn atoms to form distorted GeEu4Zn4 tetrahedra that share corners with twelve equivalent ZnEu4Ge4 tetrahedra, edges with two equivalent ZnEu4Ge4 tetrahedra, edges with four equivalent GeEu4Zn4 tetrahedra, and faces with four equivalent GeEu4Zn4 tetrahedra. In the second Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent Eu and five Zn atoms.