Données cristallographiques sur les sulfates acides M^IIIH(SO₄)₂.4H₂O avec M=Al, Ga, In, Tl, V, Fe et Ti

InH(SO₄)₂.4H₂O is orthorhombic, space group Pna2₁ or Pnam; the cell dimensions are a = 9.997 (3), b = 5.477 (2), c = 18.443 (10) Å (Z = 4). The compounds in the series M^IIIH(SO₄)₂.4H₂O (M = Al, Ga, Tl, V, Fe Ti) are isotypic. Crystal parameters and powder diffraction data are given.