Gd5Si4 crystallizes in the triclinic P1 space group. There are twenty inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 6-coordinate geometry to one Si(1), one Si(11), one Si(15), one Si(16), one Si(5), and one Si(8) atom. In the second Gd site, Gd(2) is bonded in a 6-coordinate geometry to one Si(12), one Si(15), one Si(16), one Si(2), one Si(6), and one Si(7) atom. In the third Gd site, Gd(3) is bonded in a 6-coordinate geometry to one Si(13), one Si(14), one Si(3), one Si(6), one Si(7), and one Si(9) atom. In the fourth Gd site, Gd(4) is bonded in a 6-coordinate geometry to one Si(1), one Si(10), one Si(13), one Si(14), one Si(4), one Si(5), and one Si(8) atom. In the fifth Gd site, Gd(5) is bonded in a 6-coordinate geometry to one Si(1), one Si(13), one Si(14), one Si(4), one Si(5), one Si(8), and one Si(9) atom. In the sixth Gd site, Gd(6) is bonded in a 6-coordinate geometry to one Si(10), one Si(13), one Si(14), one Si(2), one Si(3), and one Si(6) atom. In the seventh Gd site, Gd(7) is bonded in a 6-coordinate geometry to one Si(11), one Si(15), one Si(16), one Si(2), one Si(3), and one Si(7) atom. In the eighth Gd site, Gd(8) is bonded in a 6-coordinate geometry to one Si(1), one Si(12), one Si(15), one Si(16), one Si(4), one Si(5), and one Si(8) atom. In the ninth Gd site, Gd(9) is bonded in a 6-coordinate geometry to one Si(1), one Si(11), one Si(12), one Si(15), one Si(4), and one Si(8) atom. In the tenth Gd site, Gd(10) is bonded in a 6-coordinate geometry to one Si(11), one Si(12), one Si(16), one Si(2), one Si(3), and one Si(7) atom. In the eleventh Gd site, Gd(11) is bonded in a 6-coordinate geometry to one Si(10), one Si(13), one Si(2), one Si(3), one Si(6), and one Si(9) atom. In the twelfth Gd site, Gd(12) is bonded in a 6-coordinate geometry to one Si(1), one Si(10), one Si(14), one Si(4), one Si(5), and one Si(9) atom. In the thirteenth Gd site, Gd(13) is bonded in a 6-coordinate geometry to one Si(10), one Si(13), one Si(4), one Si(5), one Si(8), and one Si(9) atom. In the fourteenth Gd site, Gd(14) is bonded in a 6-coordinate geometry to one Si(10), one Si(14), one Si(3), one Si(6), one Si(7), and one Si(9) atom. In the fifteenth Gd site, Gd(15) is bonded in a 6-coordinate geometry to one Si(11), one Si(12), one Si(15), one Si(2), one Si(6), and one Si(7) atom. In the sixteenth Gd site, Gd(16) is bonded in a 6-coordinate geometry to one Si(1), one Si(11), one Si(12), one Si(16), one Si(5), and one Si(8) atom. In the seventeenth Gd site, Gd(17) is bonded to one Si(10), one Si(13), one Si(14), one Si(3), one Si(5), and one Si(9) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. In the eighteenth Gd site, Gd(18) is bonded to one Si(10), one Si(13), one Si(14), one Si(4), one Si(6), and one Si(9) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. In the nineteenth Gd site, Gd(19) is bonded to one Si(1), one Si(11), one Si(12), one Si(15), one Si(16), and one Si(7) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. In the twentieth Gd site, Gd(20) is bonded to one Si(11), one Si(12), one Si(15), one Si(16), one Si(2), and one Si(8) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. There are sixteen inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(12), one Gd(16), one Gd(19), one Gd(4), one Gd(5), one Gd(8), one Gd(9), and one Si(5) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Gd(10), one Gd(11), one Gd(15), one Gd(2), one Gd(20), one Gd(6), one Gd(7), and one Si(6) atom. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Gd(10), one Gd(11), one Gd(14), one Gd(17), one Gd(3), one Gd(6), one Gd(7), and one Si(7) atom. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to one Gd(12), one Gd(13), one Gd(18), one Gd(4), one Gd(5), one Gd(8), one Gd(9), and one Si(8) atom. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(12), one Gd(13), one Gd(16), one Gd(17), one Gd(4), one Gd(5), one Gd(8), and one Si(1) atom. In the sixth Si site, Si(6) is bonded in a 8-coordinate geometry to one Gd(11), one Gd(14), one Gd(15), one Gd(18), one Gd(2), one Gd(3), one Gd(6), and one Si(2) atom. In the seventh Si site, Si(7) is bonded in a 8-coordinate geometry to one Gd(10), one Gd(14), one Gd(15), one Gd(19), one Gd(2), one Gd(3), one Gd(7), and one Si(3) atom. In the eighth Si site, Si(8) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(13), one Gd(16), one Gd(20), one Gd(4), one Gd(5), one Gd(8), one Gd(9), and one Si(4) atom. In the ninth Si site, Si(9) is bonded in a 9-coordinate geometry to one Gd(11), one Gd(12), one Gd(13), one Gd(14), one Gd(17), one Gd(18), one Gd(3), one Gd(5), and one Si(13) atom. In the tenth Si site, Si(10) is bonded in a 9-coordinate geometry to one Gd(11), one Gd(12), one Gd(13), one Gd(14), one Gd(17), one Gd(18), one Gd(4), one Gd(6), and one Si(14) atom. In the eleventh Si site, Si(11) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(10), one Gd(15), one Gd(16), one Gd(19), one Gd(20), one Gd(7), one Gd(9), and one Si(15) atom. In the twelfth Si site, Si(12) is bonded in a 9-coordinate geometry to one Gd(10), one Gd(15), one Gd(16), one Gd(19), one Gd(2), one Gd(20), one Gd(8), one Gd(9), and one Si(16) atom. In the thirteenth Si site, Si(13) is bonded in a 9-coordinate geometry to one Gd(11), one Gd(13), one Gd(17), one Gd(18), one Gd(3), one Gd(4), one Gd(5), one Gd(6), and one Si(9) atom. In the fourteenth Si site, Si(14) is bonded in a 9-coordinate geometry to one Gd(12), one Gd(14), one Gd(17), one Gd(18), one Gd(3), one Gd(4), one Gd(5), one Gd(6), and one Si(10) atom. In the fifteenth Si site, Si(15) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(15), one Gd(19), one Gd(2), one Gd(20), one Gd(7), one Gd(8), one Gd(9), and one Si(11) atom. In the sixteenth Si site, Si(16) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(10), one Gd(16), one Gd(19), one Gd(2), one Gd(20), one Gd(7), one Gd(8), and one Si(12) atom.
Gd5Si4 crystallizes in the triclinic P1 space group. There are twenty inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 6-coordinate geometry to one Si(1), one Si(11), one Si(15), one Si(16), one Si(5), and one Si(8) atom. The Gd(1)-Si(1) bond length is 3.10 Å. The Gd(1)-Si(11) bond length is 3.16 Å. The Gd(1)-Si(15) bond length is 3.16 Å. The Gd(1)-Si(16) bond length is 3.14 Å. The Gd(1)-Si(5) bond length is 3.15 Å. The Gd(1)-Si(8) bond length is 3.07 Å. In the second Gd site, Gd(2) is bonded in a 6-coordinate geometry to one Si(12), one Si(15), one Si(16), one Si(2), one Si(6), and one Si(7) atom. The Gd(2)-Si(12) bond length is 3.18 Å. The Gd(2)-Si(15) bond length is 3.13 Å. The Gd(2)-Si(16) bond length is 3.15 Å. The Gd(2)-Si(2) bond length is 3.09 Å. The Gd(2)-Si(6) bond length is 3.15 Å. The Gd(2)-Si(7) bond length is 3.09 Å. In the third Gd site, Gd(3) is bonded in a 6-coordinate geometry to one Si(13), one Si(14), one Si(3), one Si(6), one Si(7), and one Si(9) atom. The Gd(3)-Si(13) bond length is 3.16 Å. The Gd(3)-Si(14) bond length is 3.15 Å. The Gd(3)-Si(3) bond length is 3.11 Å. The Gd(3)-Si(6) bond length is 3.09 Å. The Gd(3)-Si(7) bond length is 3.17 Å. The Gd(3)-Si(9) bond length is 3.18 Å. In the fourth Gd site, Gd(4) is bonded in a 6-coordinate geometry to one Si(1), one Si(10), one Si(13), one Si(14), one Si(4), one Si(5), and one Si(8) atom. The Gd(4)-Si(1) bond length is 3.73 Å. The Gd(4)-Si(10) bond length is 3.18 Å. The Gd(4)-Si(13) bond length is 3.14 Å. The Gd(4)-Si(14) bond length is 3.15 Å. The Gd(4)-Si(4) bond length is 3.09 Å. The Gd(4)-Si(5) bond length is 3.08 Å. The Gd(4)-Si(8) bond length is 3.14 Å. In the fifth Gd site, Gd(5) is bonded in a 6-coordinate geometry to one Si(1), one Si(13), one Si(14), one Si(4), one Si(5), one Si(8), and one Si(9) atom. The Gd(5)-Si(1) bond length is 3.14 Å. The Gd(5)-Si(13) bond length is 3.17 Å. The Gd(5)-Si(14) bond length is 3.14 Å. The Gd(5)-Si(4) bond length is 3.08 Å. The Gd(5)-Si(5) bond length is 3.09 Å. The Gd(5)-Si(8) bond length is 3.73 Å. The Gd(5)-Si(9) bond length is 3.19 Å. In the sixth Gd site, Gd(6) is bonded in a 6-coordinate geometry to one Si(10), one Si(13), one Si(14), one Si(2), one Si(3), and one Si(6) atom. The Gd(6)-Si(10) bond length is 3.17 Å. The Gd(6)-Si(13) bond length is 3.14 Å. The Gd(6)-Si(14) bond length is 3.17 Å. The Gd(6)-Si(2) bond length is 3.18 Å. The Gd(6)-Si(3) bond length is 3.08 Å. The Gd(6)-Si(6) bond length is 3.12 Å. In the seventh Gd site, Gd(7) is bonded in a 6-coordinate geometry to one Si(11), one Si(15), one Si(16), one Si(2), one Si(3), and one Si(7) atom. The Gd(7)-Si(11) bond length is 3.16 Å. The Gd(7)-Si(15) bond length is 3.16 Å. The Gd(7)-Si(16) bond length is 3.11 Å. The Gd(7)-Si(2) bond length is 3.07 Å. The Gd(7)-Si(3) bond length is 3.16 Å. The Gd(7)-Si(7) bond length is 3.10 Å. In the eighth Gd site, Gd(8) is bonded in a 6-coordinate geometry to one Si(1), one Si(12), one Si(15), one Si(16), one Si(4), one Si(5), and one Si(8) atom. The Gd(8)-Si(1) bond length is 3.08 Å. The Gd(8)-Si(12) bond length is 3.17 Å. The Gd(8)-Si(15) bond length is 3.13 Å. The Gd(8)-Si(16) bond length is 3.16 Å. The Gd(8)-Si(4) bond length is 3.14 Å. The Gd(8)-Si(5) bond length is 3.73 Å. The Gd(8)-Si(8) bond length is 3.09 Å. In the ninth Gd site, Gd(9) is bonded in a 6-coordinate geometry to one Si(1), one Si(11), one Si(12), one Si(15), one Si(4), and one Si(8) atom. The Gd(9)-Si(1) bond length is 2.88 Å. The Gd(9)-Si(11) bond length is 2.98 Å. The Gd(9)-Si(12) bond length is 2.98 Å. The Gd(9)-Si(15) bond length is 3.05 Å. The Gd(9)-Si(4) bond length is 2.89 Å. The Gd(9)-Si(8) bond length is 2.98 Å. In the tenth Gd site, Gd(10) is bonded in a 6-coordinate geometry to one Si(11), one Si(12), one Si(16), one Si(2), one Si(3), and one Si(7) atom. The Gd(10)-Si(11) bond length is 2.97 Å. The Gd(10)-Si(12) bond length is 2.97 Å. The Gd(10)-Si(16) bond length is 3.05 Å. The Gd(10)-Si(2) bond length is 2.90 Å. The Gd(10)-Si(3) bond length is 2.93 Å. The Gd(10)-Si(7) bond length is 3.00 Å. In the eleventh Gd site, Gd(11) is bonded in a 6-coordinate geometry to one Si(10), one Si(13), one Si(2), one Si(3), one Si(6), and one Si(9) atom. The Gd(11)-Si(10) bond length is 2.97 Å. The Gd(11)-Si(13) bond length is 3.06 Å. The Gd(11)-Si(2) bond length is 2.92 Å. The Gd(11)-Si(3) bond length is 2.88 Å. The Gd(11)-Si(6) bond length is 2.98 Å. The Gd(11)-Si(9) bond length is 2.97 Å. In the twelfth Gd site, Gd(12) is bonded in a 6-coordinate geometry to one Si(1), one Si(10), one Si(14), one Si(4), one Si(5), and one Si(9) atom. The Gd(12)-Si(1) bond length is 2.90 Å. The Gd(12)-Si(10) bond length is 2.98 Å. The Gd(12)-Si(14) bond length is 3.06 Å. The Gd(12)-Si(4) bond length is 2.89 Å. The Gd(12)-Si(5) bond length is 2.99 Å. The Gd(12)-Si(9) bond length is 2.99 Å. In the thirteenth Gd site, Gd(13) is bonded in a 6-coordinate geometry to one Si(10), one Si(13), one Si(4), one Si(5), one Si(8), and one Si(9) atom. The Gd(13)-Si(10) bond length is 2.98 Å. The Gd(13)-Si(13) bond length is 3.06 Å. The Gd(13)-Si(4) bond length is 2.98 Å. The Gd(13)-Si(5) bond length is 2.88 Å. The Gd(13)-Si(8) bond length is 2.90 Å. The Gd(13)-Si(9) bond length is 2.98 Å. In the fourteenth Gd site, Gd(14) is bonded in a 6-coordinate geometry to one Si(10), one Si(14), one Si(3), one Si(6), one Si(7), and one Si(9) atom. The Gd(14)-Si(10) bond length is 2.98 Å. The Gd(14)-Si(14) bond length is 3.06 Å. The Gd(14)-Si(3) bond length is 3.00 Å. The Gd(14)-Si(6) bond length is 2.89 Å. The Gd(14)-Si(7) bond length is 2.92 Å. The Gd(14)-Si(9) bond length is 2.98 Å. In the fifteenth Gd site, Gd(15) is bonded in a 6-coordinate geometry to one Si(11), one Si(12), one Si(15), one Si(2), one Si(6), and one Si(7) atom. The Gd(15)-Si(11) bond length is 2.98 Å. The Gd(15)-Si(12) bond length is 2.97 Å. The Gd(15)-Si(15) bond length is 3.04 Å. The Gd(15)-Si(2) bond length is 3.00 Å. The Gd(15)-Si(6) bond length is 2.93 Å. The Gd(15)-Si(7) bond length is 2.91 Å. In the sixteenth Gd site, Gd(16) is bonded in a 6-coordinate geometry to one Si(1), one Si(11), one Si(12), one Si(16), one Si(5), and one Si(8) atom. The Gd(16)-Si(1) bond length is 2.99 Å. The Gd(16)-Si(11) bond length is 2.97 Å. The Gd(16)-Si(12) bond length is 2.97 Å. The Gd(16)-Si(16) bond length is 3.06 Å. The Gd(16)-Si(5) bond length is 2.91 Å. The Gd(16)-Si(8) bond length is 2.88 Å. In the seventeenth Gd site, Gd(17) is bonded to one Si(10), one Si(13), one Si(14), one Si(3), one Si(5), and one Si(9) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. The Gd(17)-Si(10) bond length is 2.95 Å. The Gd(17)-Si(13) bond length is 2.96 Å. The Gd(17)-Si(14) bond length is 3.04 Å. The Gd(17)-Si(3) bond length is 3.15 Å. The Gd(17)-Si(5) bond length is 3.11 Å. The Gd(17)-Si(9) bond length is 3.32 Å. In the eighteenth Gd site, Gd(18) is bonded to one Si(10), one Si(13), one Si(14), one Si(4), one Si(6), and one Si(9) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. The Gd(18)-Si(10) bond length is 3.31 Å. The Gd(18)-Si(13) bond length is 3.01 Å. The Gd(18)-Si(14) bond length is 2.96 Å. The Gd(18)-Si(4) bond length is 3.10 Å. The Gd(18)-Si(6) bond length is 3.16 Å. The Gd(18)-Si(9) bond length is 2.98 Å. In the nineteenth Gd site, Gd(19) is bonded to one Si(1), one Si(11), one Si(12), one Si(15), one Si(16), and one Si(7) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. The Gd(19)-Si(1) bond length is 3.11 Å. The Gd(19)-Si(11) bond length is 3.34 Å. The Gd(19)-Si(12) bond length is 2.97 Å. The Gd(19)-Si(15) bond length is 2.95 Å. The Gd(19)-Si(16) bond length is 3.03 Å. The Gd(19)-Si(7) bond length is 3.13 Å. In the twentieth Gd site, Gd(20) is bonded to one Si(11), one Si(12), one Si(15), one Si(16), one Si(2), and one Si(8) atom to form distorted corner-sharing GdSi6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. The Gd(20)-Si(11) bond length is 2.96 Å. The Gd(20)-Si(12) bond length is 3.33 Å. The Gd(20)-Si(15) bond length is 3.02 Å. The Gd(20)-Si(16) bond length is 2.94 Å. The Gd(20)-Si(2) bond length is 3.13 Å. The Gd(20)-Si(8) bond length is 3.11 Å. There are sixteen inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(12), one Gd(16), one Gd(19), one Gd(4), one Gd(5), one Gd(8), one Gd(9), and one Si(5) atom. The Si(1)-Si(5) bond length is 2.50 Å. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Gd(10), one Gd(11), one Gd(15), one Gd(2), one Gd(20), one Gd(6), one Gd(7), and one Si(6) atom. The Si(2)-Si(6) bond length is 2.50 Å. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Gd(10), one Gd(11), one Gd(14), one Gd(17), one Gd(3), one Gd(6), one Gd(7), and one Si(7) atom. The Si(3)-Si(7) bond length is 2.50 Å. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to one Gd(12), one Gd(13), one Gd(18), one Gd(4), one Gd(5), one Gd(8), one Gd(9), and one Si(8) atom. The Si(4)-Si(8) bond length is 2.49 Å. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(12), one Gd(13), one Gd(16), one Gd(17), one Gd(4), one Gd(5), one Gd(8), and one Si(1) atom. In the sixth Si site, Si(6) is bonded in a 8-coordinate geometry to one Gd(11), one Gd(14), one Gd(15), one Gd(18), one Gd(2), one Gd(3), one Gd(6), and one Si(2) atom. In the seventh Si site, Si(7) is bonded in a 8-coordinate geometry to one Gd(10), one Gd(14), one Gd(15), one Gd(19), one Gd(2), one Gd(3), one Gd(7), and one Si(3) atom. In the eighth Si site, Si(8) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(13), one Gd(16), one Gd(20), one Gd(4), one Gd(5), one Gd(8), one Gd(9), and one Si(4) atom. In the ninth Si site, Si(9) is bonded in a 9-coordinate geometry to one Gd(11), one Gd(12), one Gd(13), one Gd(14), one Gd(17), one Gd(18), one Gd(3), one Gd(5), and one Si(13) atom. The Si(9)-Si(13) bond length is 2.50 Å. In the tenth Si site, Si(10) is bonded in a 9-coordinate geometry to one Gd(11), one Gd(12), one Gd(13), one Gd(14), one Gd(17), one Gd(18), one Gd(4), one Gd(6), and one Si(14) atom. The Si(10)-Si(14) bond length is 2.50 Å. In the eleventh Si site, Si(11) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(10), one Gd(15), one Gd(16), one Gd(19), one Gd(20), one Gd(7), one Gd(9), and one Si(15) atom. The Si(11)-Si(15) bond length is 2.50 Å. In the twelfth Si site, Si(12) is bonded in a 9-coordinate geometry to one Gd(10), one Gd(15), one Gd(16), one Gd(19), one Gd(2), one Gd(20), one Gd(8), one Gd(9), and one Si(16) atom. The Si(12)-Si(16) bond length is 2.51 Å. In the thirteenth Si site, Si(13) is bonded in a 9-coordinate geometry to one Gd(11), one Gd(13), one Gd(17), one Gd(18), one Gd(3), one Gd(4), one Gd(5), one Gd(6), and one Si(9) atom. In the fourteenth Si site, Si(14) is bonded in a 9-coordinate geometry to one Gd(12), one Gd(14), one Gd(17), one Gd(18), one Gd(3), one Gd(4), one Gd(5), one Gd(6), and one Si(10) atom. In the fifteenth Si site, Si(15) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(15), one Gd(19), one Gd(2), one Gd(20), one Gd(7), one Gd(8), one Gd(9), and one Si(11) atom. In the sixteenth Si site, Si(16) is bonded in a 9-coordinate geometry to one Gd(1), one Gd(10), one Gd(16), one Gd(19), one Gd(2), one Gd(20), one Gd(7), one Gd(8), and one Si(12) atom.