TaOs3 is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. Ta(1) is bonded to twelve Os(1,1,1) atoms to form TaOs12 cuboctahedra that share corners with six equivalent Ta(1)Os12 cuboctahedra; corners with twelve Os(1,1)Ta4Os8 cuboctahedra; edges with eighteen Os(1,1,1)Ta4Os8 cuboctahedra; faces with eight equivalent Ta(1)Os12 cuboctahedra; and faces with twelve Os(1,1,1)Ta4Os8 cuboctahedra. There are three inequivalent Os sites. In the first Os site, Os(1) is bonded to four equivalent Ta(1) and eight Os(1,1,1) atoms to form distorted OsTa4Os8 cuboctahedra that share corners with four equivalent Ta(1)Os12 cuboctahedra; corners with fourteen Os(1,1)Ta4Os8 cuboctahedra; edges with six equivalent Ta(1)Os12 cuboctahedra; edges with twelve Os(1,1,1)Ta4Os8 cuboctahedra; faces with four equivalent Ta(1)Os12 cuboctahedra; and faces with sixteen Os(1,1,1)Ta4Os8 cuboctahedra. In the second Os site, Os(1) is bonded to four equivalent Ta(1) and eight equivalent Os(1) atoms to form distorted OsTa4Os8 cuboctahedra that share corners with four equivalent Ta(1)Os12 cuboctahedra; corners with fourteen Os(1,1)Ta4Os8 cuboctahedra; edges with six equivalent Ta(1)Os12 cuboctahedra; edges with twelve equivalent Os(1)Ta4Os8 cuboctahedra; faces with four equivalent Ta(1)Os12 cuboctahedra; and faces with sixteen Os(1,1,1)Ta4Os8 cuboctahedra. In the third Os site, Os(1) is bonded to four equivalent Ta(1) and eight equivalent Os(1) atoms to form distorted OsTa4Os8 cuboctahedra that share corners with four equivalent Ta(1)Os12 cuboctahedra; corners with fourteen Os(1,1)Ta4Os8 cuboctahedra; edges with six equivalent Ta(1)Os12 cuboctahedra; edges with twelve equivalent Os(1)Ta4Os8 cuboctahedra; faces with four equivalent Ta(1)Os12 cuboctahedra; and faces with sixteen Os(1,1,1)Ta4Os8 cuboctahedra.
TaOs3 is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. Ta(1) is bonded to twelve Os(1,1,1) atoms to form TaOs12 cuboctahedra that share corners with six equivalent Ta(1)Os12 cuboctahedra; corners with twelve Os(1,1)Ta4Os8 cuboctahedra; edges with eighteen Os(1,1,1)Ta4Os8 cuboctahedra; faces with eight equivalent Ta(1)Os12 cuboctahedra; and faces with twelve Os(1,1,1)Ta4Os8 cuboctahedra. There are six shorter (2.75 Å) and six longer (2.79 Å) Ta(1)-Os(1,1,1) bond lengths. There are three inequivalent Os sites. In the first Os site, Os(1) is bonded to four equivalent Ta(1) and eight Os(1,1,1) atoms to form distorted OsTa4Os8 cuboctahedra that share corners with four equivalent Ta(1)Os12 cuboctahedra; corners with fourteen Os(1,1)Ta4Os8 cuboctahedra; edges with six equivalent Ta(1)Os12 cuboctahedra; edges with twelve Os(1,1,1)Ta4Os8 cuboctahedra; faces with four equivalent Ta(1)Os12 cuboctahedra; and faces with sixteen Os(1,1,1)Ta4Os8 cuboctahedra. There are a spread of Os(1)-Os(1,1,1) bond distances ranging from 2.74-2.81 Å. In the second Os site, Os(1) is bonded to four equivalent Ta(1) and eight equivalent Os(1) atoms to form distorted OsTa4Os8 cuboctahedra that share corners with four equivalent Ta(1)Os12 cuboctahedra; corners with fourteen Os(1,1)Ta4Os8 cuboctahedra; edges with six equivalent Ta(1)Os12 cuboctahedra; edges with twelve equivalent Os(1)Ta4Os8 cuboctahedra; faces with four equivalent Ta(1)Os12 cuboctahedra; and faces with sixteen Os(1,1,1)Ta4Os8 cuboctahedra. In the third Os site, Os(1) is bonded to four equivalent Ta(1) and eight equivalent Os(1) atoms to form distorted OsTa4Os8 cuboctahedra that share corners with four equivalent Ta(1)Os12 cuboctahedra; corners with fourteen Os(1,1)Ta4Os8 cuboctahedra; edges with six equivalent Ta(1)Os12 cuboctahedra; edges with twelve equivalent Os(1)Ta4Os8 cuboctahedra; faces with four equivalent Ta(1)Os12 cuboctahedra; and faces with sixteen Os(1,1,1)Ta4Os8 cuboctahedra.