Accurate intensity integration in the twinned γ-form of o-nitroaniline

Abstract

o-Nitroaniline, C6H6N2O3, is known to be polymorphic. The α-form is probably amorphous, while the β- and γ-forms are crystalline. Difficulties with the unit-cell determination of the γ-form were reported as a consequence of twinning. In this paper, newly recorded diffraction data of the γ-form of o-nitroaniline are described that were processed taking into account the two twin lattices. Data were partly deconvoluted and much better agreement was obtained in terms of R 1 values and C—C bond precision. The availability of raw data and proper reprocessing using twin lattices is by far superior to efforts to de-twin processed structure factors.