Ni25Si9 crystallizes in the trigonal P-3 space group. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 13-coordinate geometry to one Ni(3), one Ni(5), three equivalent Ni(1), four equivalent Ni(6), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to three equivalent Ni(6), six equivalent Ni(7), and three equivalent Si(1) atoms. In the third Ni site, Ni(3) is bonded in a 8-coordinate geometry to one Ni(4), three equivalent Ni(1), three equivalent Ni(6), one Si(3), and three equivalent Si(1) atoms. In the fourth Ni site, Ni(4) is bonded in a distorted body-centered cubic geometry to two equivalent Ni(3) and six equivalent Ni(7) atoms. In the fifth Ni site, Ni(5) is bonded in a 13-coordinate geometry to three equivalent Ni(1), three equivalent Ni(6), three equivalent Ni(7), one Si(2), and three equivalent Si(1) atoms. In the sixth Ni site, Ni(6) is bonded in a 11-coordinate geometry to one Ni(2), one Ni(3), one Ni(5), one Ni(7), four equivalent Ni(1), one Si(2), and two equivalent Si(1) atoms. In the seventh Ni site, Ni(7) is bonded in a 12-coordinate geometry to one Ni(4), one Ni(5), one Ni(6), two equivalent Ni(2), three equivalent Ni(7), and four equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ni(1), one Ni(2), one Ni(3), one Ni(5), two equivalent Ni(6), and four equivalent Ni(7) atoms. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to one Ni(5), three equivalent Ni(6), and six equivalent Ni(1) atoms. In the third Si site, Si(3) is bonded in a body-centered cubic geometry to two equivalent Ni(3) and six equivalent Ni(1) atoms.
Ni25Si9 crystallizes in the trigonal P-3 space group. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 13-coordinate geometry to one Ni(3), one Ni(5), three equivalent Ni(1), four equivalent Ni(6), one Si(1), one Si(3), and two equivalent Si(2) atoms. The Ni(1)-Ni(3) bond length is 2.68 Å. The Ni(1)-Ni(5) bond length is 2.55 Å. There are two shorter (2.57 Å) and one longer (2.82 Å) Ni(1)-Ni(1) bond length. There are a spread of Ni(1)-Ni(6) bond distances ranging from 2.45-2.63 Å. The Ni(1)-Si(1) bond length is 2.38 Å. The Ni(1)-Si(3) bond length is 2.25 Å. There is one shorter (2.25 Å) and one longer (2.52 Å) Ni(1)-Si(2) bond length. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to three equivalent Ni(6), six equivalent Ni(7), and three equivalent Si(1) atoms. All Ni(2)-Ni(6) bond lengths are 2.60 Å. There are three shorter (2.50 Å) and three longer (2.53 Å) Ni(2)-Ni(7) bond lengths. All Ni(2)-Si(1) bond lengths are 2.26 Å. In the third Ni site, Ni(3) is bonded in a 8-coordinate geometry to one Ni(4), three equivalent Ni(1), three equivalent Ni(6), one Si(3), and three equivalent Si(1) atoms. The Ni(3)-Ni(4) bond length is 2.43 Å. All Ni(3)-Ni(6) bond lengths are 2.50 Å. The Ni(3)-Si(3) bond length is 2.33 Å. All Ni(3)-Si(1) bond lengths are 2.33 Å. In the fourth Ni site, Ni(4) is bonded in a distorted body-centered cubic geometry to two equivalent Ni(3) and six equivalent Ni(7) atoms. All Ni(4)-Ni(7) bond lengths are 2.41 Å. In the fifth Ni site, Ni(5) is bonded in a 13-coordinate geometry to three equivalent Ni(1), three equivalent Ni(6), three equivalent Ni(7), one Si(2), and three equivalent Si(1) atoms. All Ni(5)-Ni(6) bond lengths are 2.54 Å. All Ni(5)-Ni(7) bond lengths are 2.63 Å. The Ni(5)-Si(2) bond length is 2.49 Å. All Ni(5)-Si(1) bond lengths are 2.39 Å. In the sixth Ni site, Ni(6) is bonded in a 11-coordinate geometry to one Ni(2), one Ni(3), one Ni(5), one Ni(7), four equivalent Ni(1), one Si(2), and two equivalent Si(1) atoms. The Ni(6)-Ni(7) bond length is 2.46 Å. The Ni(6)-Si(2) bond length is 2.34 Å. There is one shorter (2.33 Å) and one longer (2.41 Å) Ni(6)-Si(1) bond length. In the seventh Ni site, Ni(7) is bonded in a 12-coordinate geometry to one Ni(4), one Ni(5), one Ni(6), two equivalent Ni(2), three equivalent Ni(7), and four equivalent Si(1) atoms. There is one shorter (2.52 Å) and two longer (2.65 Å) Ni(7)-Ni(7) bond lengths. There are a spread of Ni(7)-Si(1) bond distances ranging from 2.25-2.74 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ni(1), one Ni(2), one Ni(3), one Ni(5), two equivalent Ni(6), and four equivalent Ni(7) atoms. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to one Ni(5), three equivalent Ni(6), and six equivalent Ni(1) atoms. In the third Si site, Si(3) is bonded in a body-centered cubic geometry to two equivalent Ni(3) and six equivalent Ni(1) atoms.