NiSe2 is Pyrite structured and crystallizes in the orthorhombic Pbca space group. Ni(1) is bonded to six equivalent Se(1) atoms to form NiSe6 octahedra that share corners with twelve equivalent Ni(1)Se6 octahedra and corners with six equivalent Se(1)Ni3Se tetrahedra. The corner-sharing octahedral tilt angles range from 64-65°. Se(1) is bonded to three equivalent Ni(1) and one Se(1) atom to form distorted SeNi3Se tetrahedra that share corners with three equivalent Ni(1)Se6 octahedra and corners with fifteen equivalent Se(1)Ni3Se tetrahedra. The corner-sharing octahedral tilt angles range from 77-78°.
NiSe2 is Pyrite structured and crystallizes in the orthorhombic Pbca space group. Ni(1) is bonded to six equivalent Se(1) atoms to form NiSe6 octahedra that share corners with twelve equivalent Ni(1)Se6 octahedra and corners with six equivalent Se(1)Ni3Se tetrahedra. The corner-sharing octahedral tilt angles range from 64-65°. All Ni(1)-Se(1) bond lengths are 2.52 Å. Se(1) is bonded to three equivalent Ni(1) and one Se(1) atom to form distorted SeNi3Se tetrahedra that share corners with three equivalent Ni(1)Se6 octahedra and corners with fifteen equivalent Se(1)Ni3Se tetrahedra. The corner-sharing octahedral tilt angles range from 77-78°. The Se(1)-Se(1) bond length is 2.39 Å.