Tb4GeSi3 crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one Ge(1), two equivalent Si(1), and four equivalent Si(2) atoms. In the second Tb site, Tb(2) is bonded in a 7-coordinate geometry to two equivalent Ge(1), one Si(1), and four equivalent Si(3) atoms. In the third Tb site, Tb(3) is bonded in a 7-coordinate geometry to four equivalent Ge(1), one Si(2), and two equivalent Si(3) atoms. In the fourth Tb site, Tb(4) is bonded in a 7-coordinate geometry to one Si(3), two equivalent Si(2), and four equivalent Si(1) atoms. Ge(1) is bonded in a 9-coordinate geometry to one Tb(1), two equivalent Tb(2), four equivalent Tb(3), and two equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Tb(2), two equivalent Tb(1), four equivalent Tb(4), and two equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Tb(3), two equivalent Tb(4), four equivalent Tb(1), and two equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Tb(4), two equivalent Tb(3), four equivalent Tb(2), and two equivalent Ge(1) atoms.
Tb4GeSi3 crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one Ge(1), two equivalent Si(1), and four equivalent Si(2) atoms. The Tb(1)-Ge(1) bond length is 3.00 Å. Both Tb(1)-Si(1) bond lengths are 3.12 Å. All Tb(1)-Si(2) bond lengths are 2.97 Å. In the second Tb site, Tb(2) is bonded in a 7-coordinate geometry to two equivalent Ge(1), one Si(1), and four equivalent Si(3) atoms. Both Tb(2)-Ge(1) bond lengths are 3.18 Å. The Tb(2)-Si(1) bond length is 3.01 Å. All Tb(2)-Si(3) bond lengths are 2.96 Å. In the third Tb site, Tb(3) is bonded in a 7-coordinate geometry to four equivalent Ge(1), one Si(2), and two equivalent Si(3) atoms. All Tb(3)-Ge(1) bond lengths are 2.96 Å. The Tb(3)-Si(2) bond length is 3.01 Å. Both Tb(3)-Si(3) bond lengths are 3.18 Å. In the fourth Tb site, Tb(4) is bonded in a 7-coordinate geometry to one Si(3), two equivalent Si(2), and four equivalent Si(1) atoms. The Tb(4)-Si(3) bond length is 2.98 Å. Both Tb(4)-Si(2) bond lengths are 3.14 Å. All Tb(4)-Si(1) bond lengths are 2.97 Å. Ge(1) is bonded in a 9-coordinate geometry to one Tb(1), two equivalent Tb(2), four equivalent Tb(3), and two equivalent Si(3) atoms. Both Ge(1)-Si(3) bond lengths are 2.57 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Tb(2), two equivalent Tb(1), four equivalent Tb(4), and two equivalent Si(2) atoms. Both Si(1)-Si(2) bond lengths are 2.51 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Tb(3), two equivalent Tb(4), four equivalent Tb(1), and two equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Tb(4), two equivalent Tb(3), four equivalent Tb(2), and two equivalent Ge(1) atoms.