Pm3Si is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Pm(1) is bonded to eight equivalent Pm(1) and four equivalent Si(1) atoms to form distorted PmPm8Si4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Si4 cuboctahedra, edges with eight equivalent Si(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Si4 cuboctahedra, faces with four equivalent Si(1)Pm12 cuboctahedra, and faces with fourteen equivalent Pm(1)Pm8Si4 cuboctahedra. Si(1) is bonded to twelve equivalent Pm(1) atoms to form SiPm12 cuboctahedra that share corners with twelve equivalent Si(1)Pm12 cuboctahedra, edges with twenty-four equivalent Pm(1)Pm8Si4 cuboctahedra, faces with six equivalent Si(1)Pm12 cuboctahedra, and faces with twelve equivalent Pm(1)Pm8Si4 cuboctahedra.
Pm3Si is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Pm(1) is bonded to eight equivalent Pm(1) and four equivalent Si(1) atoms to form distorted PmPm8Si4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Si4 cuboctahedra, edges with eight equivalent Si(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Si4 cuboctahedra, faces with four equivalent Si(1)Pm12 cuboctahedra, and faces with fourteen equivalent Pm(1)Pm8Si4 cuboctahedra. All Pm(1)-Pm(1) bond lengths are 3.35 Å. All Pm(1)-Si(1) bond lengths are 3.35 Å. Si(1) is bonded to twelve equivalent Pm(1) atoms to form SiPm12 cuboctahedra that share corners with twelve equivalent Si(1)Pm12 cuboctahedra, edges with twenty-four equivalent Pm(1)Pm8Si4 cuboctahedra, faces with six equivalent Si(1)Pm12 cuboctahedra, and faces with twelve equivalent Pm(1)Pm8Si4 cuboctahedra.