Si5C3 crystallizes in the trigonal R3 space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal planar geometry to three equivalent C(1) atoms. In the second Si site, Si(2) is bonded in a distorted bent 120 degrees geometry to one Si(3) and two equivalent C(1) atoms. In the third Si site, Si(3) is bonded in a 3-coordinate geometry to three equivalent Si(2) atoms. C(1) is bonded in a trigonal planar geometry to one Si(1) and two equivalent Si(2) atoms.
Si5C3 crystallizes in the trigonal R3 space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal planar geometry to three equivalent C(1) atoms. All Si(1)-C(1) bond lengths are 1.85 Å. In the second Si site, Si(2) is bonded in a distorted bent 120 degrees geometry to one Si(3) and two equivalent C(1) atoms. The Si(2)-Si(3) bond length is 2.34 Å. There is one shorter (1.78 Å) and one longer (1.79 Å) Si(2)-C(1) bond length. In the third Si site, Si(3) is bonded in a 3-coordinate geometry to three equivalent Si(2) atoms. C(1) is bonded in a trigonal planar geometry to one Si(1) and two equivalent Si(2) atoms.