▎ 摘　　要

Using conventional powder diffractometry and monochromatic Cu Kalpha X-rays, five of the Argonne Premium Coals have been examined in an attempt to better understand their molecular-level structuring. The diffractograms have been separated into contributions from mineral diffraction, amorphous scattering, and nonideal diffraction, with the latter due to small and nearly planar polycyclic aromatics termed graphenes. Correlation of the diffuse graphene layer stacking peak in each diffractogram with the percentage of aliphatic carbon in the coal suggests that the aliphatic moieties in these bituminous coals cause distortions (nonuniform strains) in the stacking of the graphene units which in turn cause the diffuseness of this peak.