Ta2SiAs2 crystallizes in the tetragonal P4/mmm space group. Ta(1) is bonded to four equivalent Ta(1), one Si(1), and one As(1) atom to form distorted TaTa4SiAs octahedra that share  a cornercorner with one As(1)TaAs5 octahedra, corners with five equivalent Ta(1)Ta4SiAs octahedra, edges with four equivalent Ta(1)Ta4SiAs octahedra, edges with four equivalent Si(1)Ta2Si4 octahedra, and edges with four equivalent As(1)TaAs5 octahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded to two equivalent Ta(1) and four equivalent Si(1) atoms to form distorted SiTa2Si4 octahedra that share corners with two equivalent As(1)TaAs5 octahedra, corners with four equivalent Si(1)Ta2Si4 octahedra, edges with four equivalent Si(1)Ta2Si4 octahedra, and edges with eight equivalent Ta(1)Ta4SiAs octahedra. The corner-sharing octahedra are not tilted. As(1) is bonded to one Ta(1) and five equivalent As(1) atoms to form distorted AsTaAs5 octahedra that share  a cornercorner with one Ta(1)Ta4SiAs octahedra,  a cornercorner with one Si(1)Ta2Si4 octahedra, corners with four equivalent As(1)TaAs5 octahedra, edges with four equivalent Ta(1)Ta4SiAs octahedra, and edges with eight equivalent As(1)TaAs5 octahedra. The corner-sharing octahedra are not tilted.
Ta2SiAs2 crystallizes in the tetragonal P4/mmm space group. Ta(1) is bonded to four equivalent Ta(1), one Si(1), and one As(1) atom to form distorted TaTa4SiAs octahedra that share  a cornercorner with one As(1)TaAs5 octahedra, corners with five equivalent Ta(1)Ta4SiAs octahedra, edges with four equivalent Ta(1)Ta4SiAs octahedra, edges with four equivalent Si(1)Ta2Si4 octahedra, and edges with four equivalent As(1)TaAs5 octahedra. The corner-sharing octahedra are not tilted. All Ta(1)-Ta(1) bond lengths are 2.72 Å. The Ta(1)-Si(1) bond length is 2.54 Å. The Ta(1)-As(1) bond length is 2.75 Å. Si(1) is bonded to two equivalent Ta(1) and four equivalent Si(1) atoms to form distorted SiTa2Si4 octahedra that share corners with two equivalent As(1)TaAs5 octahedra, corners with four equivalent Si(1)Ta2Si4 octahedra, edges with four equivalent Si(1)Ta2Si4 octahedra, and edges with eight equivalent Ta(1)Ta4SiAs octahedra. The corner-sharing octahedra are not tilted. All Si(1)-Si(1) bond lengths are 2.72 Å. As(1) is bonded to one Ta(1) and five equivalent As(1) atoms to form distorted AsTaAs5 octahedra that share  a cornercorner with one Ta(1)Ta4SiAs octahedra,  a cornercorner with one Si(1)Ta2Si4 octahedra, corners with four equivalent As(1)TaAs5 octahedra, edges with four equivalent Ta(1)Ta4SiAs octahedra, and edges with eight equivalent As(1)TaAs5 octahedra. The corner-sharing octahedra are not tilted. There are four shorter (2.72 Å) and one longer (2.84 Å) As(1)-As(1) bond length.