International audienceA comprehensive quantification of the various phases of clinkers by X-ray diffraction with a Rietveld-like analysis is an important industrial challenge. Various available structural models are used for the most frequent M1 and M3 polymorphs of alite usually found in industrial clinkers, referred to as M1- or M3-based clinkers. In this paper, the effect of C3S structural model is investigated. Four models are tested and compared using either synthetic M1 and M3 alites or M1- and M3-based clinkers. The comparison validates the available models for M1 and M3 alites and an average model, given here, derived from our recently proposed M1 structure as a catch-all model when the nature of the clinker is unknown. The latter m...