Er2Fe6Co6P7 crystallizes in the hexagonal P-6 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 15-coordinate geometry to three equivalent Fe(2), six equivalent Co(1), and six equivalent P(3) atoms. In the second Er site, Er(2) is bonded in a 18-coordinate geometry to six equivalent Fe(2), three equivalent Co(1), three equivalent Co(2), and six equivalent P(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one P(2), two equivalent P(1), and two equivalent P(3) atoms. In the second Fe site, Fe(2) is bonded to one Er(1), two equivalent Er(2), two equivalent P(2), and two equivalent P(3) atoms to form distorted FeEr3P4 tetrahedra that share corners with two equivalent Co(2)ErP4 tetrahedra, corners with six equivalent Fe(2)Er3P4 tetrahedra, edges with two equivalent Fe(2)Er3P4 tetrahedra, edges with two equivalent Co(2)ErP4 tetrahedra, faces with two equivalent Fe(2)Er3P4 tetrahedra, and faces with two equivalent Co(2)ErP4 tetrahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 4-coordinate geometry to one Er(2), two equivalent Er(1), two equivalent P(2), and two equivalent P(3) atoms. In the second Co site, Co(2) is bonded to one Er(2), one P(1), one P(3), and two equivalent P(2) atoms to form distorted CoErP4 tetrahedra that share corners with two equivalent Fe(2)Er3P4 tetrahedra, corners with six equivalent Co(2)ErP4 tetrahedra, edges with two equivalent Fe(2)Er3P4 tetrahedra, and faces with two equivalent Fe(2)Er3P4 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 9-coordinate geometry to six equivalent Fe(1) and three equivalent Co(2) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to two equivalent Er(2), one Fe(1), two equivalent Fe(2), two equivalent Co(1), and two equivalent Co(2) atoms. In the third P site, P(3) is bonded in a 9-coordinate geometry to two equivalent Er(1), two equivalent Fe(1), two equivalent Fe(2), one Co(2), and two equivalent Co(1) atoms.
Er2Fe6Co6P7 crystallizes in the hexagonal P-6 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 15-coordinate geometry to three equivalent Fe(2), six equivalent Co(1), and six equivalent P(3) atoms. All Er(1)-Fe(2) bond lengths are 3.09 Å. All Er(1)-Co(1) bond lengths are 2.91 Å. All Er(1)-P(3) bond lengths are 2.83 Å. In the second Er site, Er(2) is bonded in a 18-coordinate geometry to six equivalent Fe(2), three equivalent Co(1), three equivalent Co(2), and six equivalent P(2) atoms. All Er(2)-Fe(2) bond lengths are 2.96 Å. All Er(2)-Co(1) bond lengths are 3.20 Å. All Er(2)-Co(2) bond lengths are 3.06 Å. All Er(2)-P(2) bond lengths are 2.84 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one P(2), two equivalent P(1), and two equivalent P(3) atoms. The Fe(1)-P(2) bond length is 2.27 Å. Both Fe(1)-P(1) bond lengths are 2.49 Å. Both Fe(1)-P(3) bond lengths are 2.52 Å. In the second Fe site, Fe(2) is bonded to one Er(1), two equivalent Er(2), two equivalent P(2), and two equivalent P(3) atoms to form distorted FeEr3P4 tetrahedra that share corners with two equivalent Co(2)ErP4 tetrahedra, corners with six equivalent Fe(2)Er3P4 tetrahedra, edges with two equivalent Fe(2)Er3P4 tetrahedra, edges with two equivalent Co(2)ErP4 tetrahedra, faces with two equivalent Fe(2)Er3P4 tetrahedra, and faces with two equivalent Co(2)ErP4 tetrahedra. There is one shorter (2.25 Å) and one longer (2.31 Å) Fe(2)-P(2) bond length. Both Fe(2)-P(3) bond lengths are 2.25 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 4-coordinate geometry to one Er(2), two equivalent Er(1), two equivalent P(2), and two equivalent P(3) atoms. Both Co(1)-P(2) bond lengths are 2.31 Å. There is one shorter (2.23 Å) and one longer (2.24 Å) Co(1)-P(3) bond length. In the second Co site, Co(2) is bonded to one Er(2), one P(1), one P(3), and two equivalent P(2) atoms to form distorted CoErP4 tetrahedra that share corners with two equivalent Fe(2)Er3P4 tetrahedra, corners with six equivalent Co(2)ErP4 tetrahedra, edges with two equivalent Fe(2)Er3P4 tetrahedra, and faces with two equivalent Fe(2)Er3P4 tetrahedra. The Co(2)-P(1) bond length is 2.14 Å. The Co(2)-P(3) bond length is 2.18 Å. Both Co(2)-P(2) bond lengths are 2.28 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 9-coordinate geometry to six equivalent Fe(1) and three equivalent Co(2) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to two equivalent Er(2), one Fe(1), two equivalent Fe(2), two equivalent Co(1), and two equivalent Co(2) atoms. In the third P site, P(3) is bonded in a 9-coordinate geometry to two equivalent Er(1), two equivalent Fe(1), two equivalent Fe(2), one Co(2), and two equivalent Co(1) atoms.