Crystal structure of β-VO(HPO4) · 2H2O solved from X-ray powder diffraction
1989; Elsevier BV; Volume: 79; Issue: 1 Linguagem: Inglês
10.1016/0022-4596(89)90262-4
ISSN1095-726X
AutoresA. Le Bail, G. Férey, Pedro Amorós, Aurelio Beltrán, G. Villeneuve,
Tópico(s)Catalysis and Oxidation Reactions
ResumoThe crystal structure of β-VO(HPO4) · 2H2O has been determined from X-ray powder diffraction data. The cell is triclinic (space group P1, Z = 4) with a = 5.659(2)Å, b = 7.578(4) Å, c = 12.623(5) Å, α = 89.66(2)°, β = 102.14(2)°, and γ = 92.23(2)°. Starting positional parameters were obtained by direct methods applied to 640 reflections which are derived from a modified Rietveld analysis working without structural model. The structure was refined using Rietveld profile refinement principles. The final reliability factors were RI = 0.039, Rp = 0.076, and Pwp = 0.092. The structure is built up of chains of corner-shared VO4(H2O)2 octahedra and (HPO4) tetrahedra alternated along the c crystallographic axis. These chains are interconnected through HPO4 groups forming layers stacked in the [100] direction. In contrast to α-VO(HPO4) · 2H2O, there are no isolated water molecules between the layers.
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