FePtSn crystallizes in the trigonal P3m1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 3-coordinate geometry to three equivalent Fe(3) and three equivalent Pt(3) atoms. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to three equivalent Fe(4) and three equivalent Pt(4) atoms. In the third Fe site, Fe(3) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(1), one Pt(2), one Pt(3), and three equivalent Sn(2) atoms. In the fourth Fe site, Fe(4) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2), one Pt(3), one Pt(4), and three equivalent Sn(3) atoms. There are four inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to three equivalent Sn(1) and three equivalent Sn(4) atoms to form distorted edge-sharing PtSn6 octahedra. In the second Pt site, Pt(2) is bonded in a 7-coordinate geometry to one Fe(3), three equivalent Sn(1), and three equivalent Sn(2) atoms. In the third Pt site, Pt(3) is bonded in a distorted body-centered cubic geometry to one Fe(3), one Fe(4), three equivalent Fe(1), and three equivalent Sn(3) atoms. In the fourth Pt site, Pt(4) is bonded in a 7-coordinate geometry to one Fe(4), three equivalent Fe(2), and three equivalent Sn(4) atoms. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent Pt(2) atoms. In the second Sn site, Sn(2) is bonded in a 6-coordinate geometry to three equivalent Fe(3) and three equivalent Pt(2) atoms. In the third Sn site, Sn(3) is bonded in a 6-coordinate geometry to three equivalent Fe(4) and three equivalent Pt(3) atoms. In the fourth Sn site, Sn(4) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent Pt(4) atoms.
FePtSn crystallizes in the trigonal P3m1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 3-coordinate geometry to three equivalent Fe(3) and three equivalent Pt(3) atoms. All Fe(1)-Fe(3) bond lengths are 2.55 Å. All Fe(1)-Pt(3) bond lengths are 2.70 Å. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to three equivalent Fe(4) and three equivalent Pt(4) atoms. All Fe(2)-Fe(4) bond lengths are 2.53 Å. All Fe(2)-Pt(4) bond lengths are 2.72 Å. In the third Fe site, Fe(3) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(1), one Pt(2), one Pt(3), and three equivalent Sn(2) atoms. The Fe(3)-Pt(2) bond length is 2.64 Å. The Fe(3)-Pt(3) bond length is 2.42 Å. All Fe(3)-Sn(2) bond lengths are 2.58 Å. In the fourth Fe site, Fe(4) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2), one Pt(3), one Pt(4), and three equivalent Sn(3) atoms. The Fe(4)-Pt(3) bond length is 2.65 Å. The Fe(4)-Pt(4) bond length is 2.41 Å. All Fe(4)-Sn(3) bond lengths are 2.62 Å. There are four inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to three equivalent Sn(1) and three equivalent Sn(4) atoms to form distorted edge-sharing PtSn6 octahedra. All Pt(1)-Sn(1) bond lengths are 2.72 Å. All Pt(1)-Sn(4) bond lengths are 2.77 Å. In the second Pt site, Pt(2) is bonded in a 7-coordinate geometry to one Fe(3), three equivalent Sn(1), and three equivalent Sn(2) atoms. All Pt(2)-Sn(1) bond lengths are 2.73 Å. All Pt(2)-Sn(2) bond lengths are 2.77 Å. In the third Pt site, Pt(3) is bonded in a distorted body-centered cubic geometry to one Fe(3), one Fe(4), three equivalent Fe(1), and three equivalent Sn(3) atoms. All Pt(3)-Sn(3) bond lengths are 2.73 Å. In the fourth Pt site, Pt(4) is bonded in a 7-coordinate geometry to one Fe(4), three equivalent Fe(2), and three equivalent Sn(4) atoms. All Pt(4)-Sn(4) bond lengths are 2.69 Å. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent Pt(2) atoms. In the second Sn site, Sn(2) is bonded in a 6-coordinate geometry to three equivalent Fe(3) and three equivalent Pt(2) atoms. In the third Sn site, Sn(3) is bonded in a 6-coordinate geometry to three equivalent Fe(4) and three equivalent Pt(3) atoms. In the fourth Sn site, Sn(4) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent Pt(4) atoms.