Refinement of the structure of solid nitromethane

Abstract
The complete determination of the crystal structure of solid nitromethane has been obtained from single crystal x‐ray diffraction and neutron powder diffraction data. The structure is orthorhombic, space group P212121 with a=5.1832 Å, b=6.2357 Å, c=8.5181 Å at T=4.2 K, and Z=4. Two models were used to describe the thermal motion of the methyl group, one with anisotropic temperature factors for the hydrogen atoms constrained to correspond to a threefold rotation around the C–N bond, and the other treating the group as a rigid body, with a tortional oscillation about the C–N bond axis.