Si crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Si(1) and seven equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to seven equivalent Si(1) atoms.
Si crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Si(1) and seven equivalent Si(2) atoms. Both Si(1)-Si(1) bond lengths are 2.80 Å. There are a spread of Si(1)-Si(2) bond distances ranging from 2.56-2.71 Å. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to seven equivalent Si(1) atoms.