La6Ni2Si3 crystallizes in the monoclinic Pm space group. There are twelve inequivalent La sites. In the first La site, La(1) is bonded in a 5-coordinate geometry to two equivalent Ni(1), one Si(3), and two equivalent Si(4) atoms. In the second La site, La(2) is bonded in a 5-coordinate geometry to one Ni(2), two equivalent Ni(1), and two equivalent Si(5) atoms. In the third La site, La(3) is bonded in a 5-coordinate geometry to one Ni(3), two equivalent Ni(1), and two equivalent Si(6) atoms. In the fourth La site, La(4) is bonded in a 5-coordinate geometry to two equivalent Ni(1), two equivalent Ni(2), and one Si(6) atom. In the fifth La site, La(5) is bonded in a 5-coordinate geometry to two equivalent Ni(1), two equivalent Ni(3), and one Si(4) atom. In the sixth La site, La(6) is bonded in a 5-coordinate geometry to two equivalent Ni(1), one Si(5), and two equivalent Si(3) atoms. In the seventh La site, La(7) is bonded in a 7-coordinate geometry to one Si(3), two equivalent Si(1), two equivalent Si(5), and two equivalent Si(6) atoms. In the eighth La site, La(8) is bonded in a 7-coordinate geometry to one Ni(2), two equivalent Si(1), two equivalent Si(4), and two equivalent Si(6) atoms. In the ninth La site, La(9) is bonded in a 7-coordinate geometry to one Ni(3), two equivalent Si(1), two equivalent Si(4), and two equivalent Si(5) atoms. In the tenth La site, La(10) is bonded in a 7-coordinate geometry to two equivalent Ni(3), one Si(6), two equivalent Si(2), and two equivalent Si(3) atoms. In the eleventh La site, La(11) is bonded in a 7-coordinate geometry to two equivalent Ni(2), one Si(4), two equivalent Si(2), and two equivalent Si(3) atoms. In the twelfth La site, La(12) is bonded in a 7-coordinate geometry to two equivalent Ni(2), two equivalent Ni(3), one Si(5), and two equivalent Si(2) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a body-centered cubic geometry to one La(1), one La(2), one La(3), one La(4), one La(5), one La(6), and two equivalent Ni(1) atoms. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to one La(2), one La(8), two equivalent La(11), two equivalent La(12), two equivalent La(4), and one Si(2) atom. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to one La(3), one La(9), two equivalent La(10), two equivalent La(12), two equivalent La(5), and one Si(2) atom. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent La(7), two equivalent La(8), two equivalent La(9), one Si(4), one Si(5), and one Si(6) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent La(10), two equivalent La(11), two equivalent La(12), one Ni(2), one Ni(3), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one La(1), one La(7), two equivalent La(10), two equivalent La(11), two equivalent La(6), and one Si(2) atom. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one La(11), one La(5), two equivalent La(1), two equivalent La(8), two equivalent La(9), and one Si(1) atom. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one La(12), one La(6), two equivalent La(2), two equivalent La(7), two equivalent La(9), and one Si(1) atom. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to one La(10), one La(4), two equivalent La(3), two equivalent La(7), two equivalent La(8), and one Si(1) atom.
La6Ni2Si3 crystallizes in the monoclinic Pm space group. There are twelve inequivalent La sites. In the first La site, La(1) is bonded in a 5-coordinate geometry to two equivalent Ni(1), one Si(3), and two equivalent Si(4) atoms. Both La(1)-Ni(1) bond lengths are 2.95 Å. The La(1)-Si(3) bond length is 3.16 Å. Both La(1)-Si(4) bond lengths are 3.18 Å. In the second La site, La(2) is bonded in a 5-coordinate geometry to one Ni(2), two equivalent Ni(1), and two equivalent Si(5) atoms. The La(2)-Ni(2) bond length is 2.98 Å. Both La(2)-Ni(1) bond lengths are 2.99 Å. Both La(2)-Si(5) bond lengths are 3.22 Å. In the third La site, La(3) is bonded in a 5-coordinate geometry to one Ni(3), two equivalent Ni(1), and two equivalent Si(6) atoms. The La(3)-Ni(3) bond length is 3.04 Å. Both La(3)-Ni(1) bond lengths are 2.96 Å. Both La(3)-Si(6) bond lengths are 3.23 Å. In the fourth La site, La(4) is bonded in a 5-coordinate geometry to two equivalent Ni(1), two equivalent Ni(2), and one Si(6) atom. Both La(4)-Ni(1) bond lengths are 2.96 Å. Both La(4)-Ni(2) bond lengths are 3.16 Å. The La(4)-Si(6) bond length is 3.14 Å. In the fifth La site, La(5) is bonded in a 5-coordinate geometry to two equivalent Ni(1), two equivalent Ni(3), and one Si(4) atom. Both La(5)-Ni(1) bond lengths are 3.01 Å. Both La(5)-Ni(3) bond lengths are 3.13 Å. The La(5)-Si(4) bond length is 3.12 Å. In the sixth La site, La(6) is bonded in a 5-coordinate geometry to two equivalent Ni(1), one Si(5), and two equivalent Si(3) atoms. Both La(6)-Ni(1) bond lengths are 2.97 Å. The La(6)-Si(5) bond length is 3.14 Å. Both La(6)-Si(3) bond lengths are 3.20 Å. In the seventh La site, La(7) is bonded in a 7-coordinate geometry to one Si(3), two equivalent Si(1), two equivalent Si(5), and two equivalent Si(6) atoms. The La(7)-Si(3) bond length is 3.20 Å. Both La(7)-Si(1) bond lengths are 3.09 Å. Both La(7)-Si(5) bond lengths are 3.24 Å. Both La(7)-Si(6) bond lengths are 3.21 Å. In the eighth La site, La(8) is bonded in a 7-coordinate geometry to one Ni(2), two equivalent Si(1), two equivalent Si(4), and two equivalent Si(6) atoms. The La(8)-Ni(2) bond length is 3.16 Å. Both La(8)-Si(1) bond lengths are 3.12 Å. Both La(8)-Si(4) bond lengths are 3.21 Å. Both La(8)-Si(6) bond lengths are 3.28 Å. In the ninth La site, La(9) is bonded in a 7-coordinate geometry to one Ni(3), two equivalent Si(1), two equivalent Si(4), and two equivalent Si(5) atoms. The La(9)-Ni(3) bond length is 3.14 Å. Both La(9)-Si(1) bond lengths are 3.12 Å. Both La(9)-Si(4) bond lengths are 3.28 Å. Both La(9)-Si(5) bond lengths are 3.21 Å. In the tenth La site, La(10) is bonded in a 7-coordinate geometry to two equivalent Ni(3), one Si(6), two equivalent Si(2), and two equivalent Si(3) atoms. Both La(10)-Ni(3) bond lengths are 3.29 Å. The La(10)-Si(6) bond length is 3.14 Å. Both La(10)-Si(2) bond lengths are 3.13 Å. Both La(10)-Si(3) bond lengths are 3.22 Å. In the eleventh La site, La(11) is bonded in a 7-coordinate geometry to two equivalent Ni(2), one Si(4), two equivalent Si(2), and two equivalent Si(3) atoms. Both La(11)-Ni(2) bond lengths are 3.19 Å. The La(11)-Si(4) bond length is 3.15 Å. Both La(11)-Si(2) bond lengths are 3.13 Å. Both La(11)-Si(3) bond lengths are 3.31 Å. In the twelfth La site, La(12) is bonded in a 7-coordinate geometry to two equivalent Ni(2), two equivalent Ni(3), one Si(5), and two equivalent Si(2) atoms. Both La(12)-Ni(2) bond lengths are 3.29 Å. Both La(12)-Ni(3) bond lengths are 3.16 Å. The La(12)-Si(5) bond length is 3.19 Å. Both La(12)-Si(2) bond lengths are 3.06 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a body-centered cubic geometry to one La(1), one La(2), one La(3), one La(4), one La(5), one La(6), and two equivalent Ni(1) atoms. There is one shorter (2.28 Å) and one longer (2.29 Å) Ni(1)-Ni(1) bond length. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to one La(2), one La(8), two equivalent La(11), two equivalent La(12), two equivalent La(4), and one Si(2) atom. The Ni(2)-Si(2) bond length is 2.44 Å. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to one La(3), one La(9), two equivalent La(10), two equivalent La(12), two equivalent La(5), and one Si(2) atom. The Ni(3)-Si(2) bond length is 2.44 Å. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent La(7), two equivalent La(8), two equivalent La(9), one Si(4), one Si(5), and one Si(6) atom. The Si(1)-Si(4) bond length is 2.44 Å. The Si(1)-Si(5) bond length is 2.45 Å. The Si(1)-Si(6) bond length is 2.44 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent La(10), two equivalent La(11), two equivalent La(12), one Ni(2), one Ni(3), and one Si(3) atom. The Si(2)-Si(3) bond length is 2.50 Å. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one La(1), one La(7), two equivalent La(10), two equivalent La(11), two equivalent La(6), and one Si(2) atom. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one La(11), one La(5), two equivalent La(1), two equivalent La(8), two equivalent La(9), and one Si(1) atom. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one La(12), one La(6), two equivalent La(2), two equivalent La(7), two equivalent La(9), and one Si(1) atom. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to one La(10), one La(4), two equivalent La(3), two equivalent La(7), two equivalent La(8), and one Si(1) atom.