title: VOPO4·H2O: a stacking faults structure studied by X-ray powder diffraction and DFT-D calculations.
abstract: The dehydration process of VOPO(4)·2H(2)O occurs in two steps corresponding to successive elimination of the two crystallographically distinct water molecules. The intermediate phase VOPO(4)·H(2)O has been stabilized for X-ray powder diffraction studies. The resulting data suggest a tetragonal cell (a = 6.2203(2) Å and c = 6.18867(7) Å), but an important anisotropy in the line broadening points out the necessity of considering a not perfectly organized structure. Because of the layered structure of this compound, density functional theory calculations including dispersion corrections have been carried out to evaluate the possible presence of stacking faults. The results of these calculations give information about the nature of the translations and their probabilities using a Boltzmann distribution. DIFFaX+ simulations of the X-ray powder diffraction pattern have been carried out using the results of the theoretical calculations and confirm the presence and nature of stacking faults.
authors.affiliation: Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, Avenue du Général Leclerc, CS 50837, 35708 Rennes Cedex 7, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Gautier
authors.forename: Nathalie
authors.initials: N
authors.lastname: Audebrand
authors.forename: Eric
authors.initials: E
authors.lastname: Furet
authors.forename: Régis
authors.initials: R
authors.lastname: Gautier
authors.forename: Eric
authors.initials: E
authors.lastname: Le Fur