OsP2 is zeta iron carbide structured and crystallizes in the orthorhombic Pnnm space group. Os(1) is bonded to six equivalent P(1) atoms to form OsP6 octahedra that share corners with eight equivalent Os(1)P6 octahedra, corners with six equivalent P(1)POs3 tetrahedra, and edges with two equivalent Os(1)P6 octahedra. The corner-sharing octahedral tilt angles are 57°. P(1) is bonded to three equivalent Os(1) and one P(1) atom to form PPOs3 tetrahedra that share corners with three equivalent Os(1)P6 octahedra, corners with thirteen equivalent P(1)POs3 tetrahedra, and  an edgeedge with one P(1)POs3 tetrahedra. The corner-sharing octahedral tilt angles range from 69-71°.
OsP2 is zeta iron carbide structured and crystallizes in the orthorhombic Pnnm space group. Os(1) is bonded to six equivalent P(1) atoms to form OsP6 octahedra that share corners with eight equivalent Os(1)P6 octahedra, corners with six equivalent P(1)POs3 tetrahedra, and edges with two equivalent Os(1)P6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are two shorter (2.36 Å) and four longer (2.38 Å) Os(1)-P(1) bond lengths. P(1) is bonded to three equivalent Os(1) and one P(1) atom to form PPOs3 tetrahedra that share corners with three equivalent Os(1)P6 octahedra, corners with thirteen equivalent P(1)POs3 tetrahedra, and  an edgeedge with one P(1)POs3 tetrahedra. The corner-sharing octahedral tilt angles range from 69-71°. The P(1)-P(1) bond length is 2.24 Å.