Does the size of a crystal matter in an X-ray crystal structure analysis of a small molecule?

Abstract

The crystal structures of C7H8FN3, C20H25Br, [Cu(H2O)2(C6H12N4)(C7H3N2O6)2]·2H2O, [SnCl(H2O)(C6H5)3(C10H8N2)]2 and [Pb(NO3)2(C3H9N3S)] refined on numerically absorption-corrected reflections to low R values although the dimensions of the crystals exceeded the diameter of the X-ray beam collimator. The R values for the organic and copper compounds were not significantly different when smaller specimens cut from the large crystals were used. For the tin complex, a large peak persisted in the difference map for all sizes, and for the lead complex, the difference Fourier map was more diffuse the smaller the specimen.