Er4Ni3Si crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Er sites. In the first Er site, Er(1) is bonded in a 7-coordinate geometry to two equivalent Ni(1), four equivalent Ni(2), and one Si(1) atom. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one Ni(1), four equivalent Ni(3), and two equivalent Si(1) atoms. In the third Er site, Er(3) is bonded in a 7-coordinate geometry to one Ni(2), two equivalent Ni(3), and four equivalent Si(1) atoms. In the fourth Er site, Er(4) is bonded in a 7-coordinate geometry to one Ni(3), two equivalent Ni(2), and four equivalent Ni(1) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 9-coordinate geometry to one Er(2), two equivalent Er(1), four equivalent Er(4), and two equivalent Ni(2) atoms. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to one Er(3), two equivalent Er(4), four equivalent Er(1), and two equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to one Er(4), two equivalent Er(3), four equivalent Er(2), and two equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to one Er(1), two equivalent Er(2), four equivalent Er(3), and two equivalent Ni(3) atoms.
Er4Ni3Si crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Er sites. In the first Er site, Er(1) is bonded in a 7-coordinate geometry to two equivalent Ni(1), four equivalent Ni(2), and one Si(1) atom. Both Er(1)-Ni(1) bond lengths are 2.89 Å. All Er(1)-Ni(2) bond lengths are 2.88 Å. The Er(1)-Si(1) bond length is 3.03 Å. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one Ni(1), four equivalent Ni(3), and two equivalent Si(1) atoms. The Er(2)-Ni(1) bond length is 2.95 Å. All Er(2)-Ni(3) bond lengths are 2.90 Å. Both Er(2)-Si(1) bond lengths are 2.91 Å. In the third Er site, Er(3) is bonded in a 7-coordinate geometry to one Ni(2), two equivalent Ni(3), and four equivalent Si(1) atoms. The Er(3)-Ni(2) bond length is 2.96 Å. Both Er(3)-Ni(3) bond lengths are 2.91 Å. All Er(3)-Si(1) bond lengths are 2.90 Å. In the fourth Er site, Er(4) is bonded in a 7-coordinate geometry to one Ni(3), two equivalent Ni(2), and four equivalent Ni(1) atoms. The Er(4)-Ni(3) bond length is 2.99 Å. Both Er(4)-Ni(2) bond lengths are 2.91 Å. All Er(4)-Ni(1) bond lengths are 2.88 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 9-coordinate geometry to one Er(2), two equivalent Er(1), four equivalent Er(4), and two equivalent Ni(2) atoms. Both Ni(1)-Ni(2) bond lengths are 2.47 Å. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to one Er(3), two equivalent Er(4), four equivalent Er(1), and two equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to one Er(4), two equivalent Er(3), four equivalent Er(2), and two equivalent Si(1) atoms. Both Ni(3)-Si(1) bond lengths are 2.45 Å. Si(1) is bonded in a 9-coordinate geometry to one Er(1), two equivalent Er(2), four equivalent Er(3), and two equivalent Ni(3) atoms.