 At −140 °C, it crystallizes in the orthorhombic space group "Pnma".Lattice parameters are "a" = 9.394 Å, "b" = 8.543 Å, and "c" = 4.959 Å.There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 3.50 g·cm−3.