FeNiTe4 is pyrite-derived structured and crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to two equivalent Te(1) and four equivalent Te(2) atoms to form FeTe6 octahedra that share corners with four equivalent Fe(1)Te6 octahedra and corners with eight equivalent Ni(1)Te6 octahedra. The corner-sharing octahedral tilt angles range from 60-63°. Ni(1) is bonded to two equivalent Te(2) and four equivalent Te(1) atoms to form NiTe6 octahedra that share corners with four equivalent Ni(1)Te6 octahedra and corners with eight equivalent Fe(1)Te6 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Ni(1) atoms. In the second Te site, Te(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one Ni(1) atom.
FeNiTe4 is pyrite-derived structured and crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to two equivalent Te(1) and four equivalent Te(2) atoms to form FeTe6 octahedra that share corners with four equivalent Fe(1)Te6 octahedra and corners with eight equivalent Ni(1)Te6 octahedra. The corner-sharing octahedral tilt angles range from 60-63°. Both Fe(1)-Te(1) bond lengths are 2.54 Å. There are two shorter (2.58 Å) and two longer (2.59 Å) Fe(1)-Te(2) bond lengths. Ni(1) is bonded to two equivalent Te(2) and four equivalent Te(1) atoms to form NiTe6 octahedra that share corners with four equivalent Ni(1)Te6 octahedra and corners with eight equivalent Fe(1)Te6 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. Both Ni(1)-Te(2) bond lengths are 2.67 Å. All Ni(1)-Te(1) bond lengths are 2.64 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Ni(1) atoms. In the second Te site, Te(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one Ni(1) atom.