Parallel model cellotetraose

X-ray powder diffraction data indicate that the unit cell for cellotetraose is triclinic (space group PI) with two tetramers per unit cell. Although there is a small preference for a parallel structure at this stage, similarities between patterns calculated for parallel and antiparallel models make it difficult to choose one over the other. In addition to the rather insensitive R values, the differences in specific reflections in the observed and the calculated patterns for different models may be used as criteria in selection of a model. 

---