OsBiSe crystallizes in the monoclinic P2_1/c space group. Os(1) is bonded in a 6-coordinate geometry to three equivalent Bi(1) and three equivalent Se(1) atoms. Bi(1) is bonded to three equivalent Os(1) and one Se(1) atom to form distorted BiOs3Se tetrahedra that share corners with four equivalent Bi(1)Os3Se tetrahedra, corners with nine equivalent Se(1)BiOs3 tetrahedra, and  an edgeedge with one Bi(1)Os3Se tetrahedra. Se(1) is bonded to three equivalent Os(1) and one Bi(1) atom to form distorted SeBiOs3 tetrahedra that share corners with four equivalent Se(1)BiOs3 tetrahedra, corners with nine equivalent Bi(1)Os3Se tetrahedra, and  an edgeedge with one Se(1)BiOs3 tetrahedra.
OsBiSe crystallizes in the monoclinic P2_1/c space group. Os(1) is bonded in a 6-coordinate geometry to three equivalent Bi(1) and three equivalent Se(1) atoms. There are a spread of Os(1)-Bi(1) bond distances ranging from 2.76-2.80 Å. There is one shorter (2.47 Å) and two longer (2.50 Å) Os(1)-Se(1) bond lengths. Bi(1) is bonded to three equivalent Os(1) and one Se(1) atom to form distorted BiOs3Se tetrahedra that share corners with four equivalent Bi(1)Os3Se tetrahedra, corners with nine equivalent Se(1)BiOs3 tetrahedra, and  an edgeedge with one Bi(1)Os3Se tetrahedra. The Bi(1)-Se(1) bond length is 2.88 Å. Se(1) is bonded to three equivalent Os(1) and one Bi(1) atom to form distorted SeBiOs3 tetrahedra that share corners with four equivalent Se(1)BiOs3 tetrahedra, corners with nine equivalent Bi(1)Os3Se tetrahedra, and  an edgeedge with one Se(1)BiOs3 tetrahedra.