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The structure of uranium oxide dihydrate, also known as meta-schoepite (UO2)4O(OH)6·5H2O, has been determined from a synthetic single crystal. The structure, at 150 K, space group Pbcn, lattice constants a = 14.6861 (4), b = 13.9799 (3) and c = 16.7063 (5) Å, consists of layers of stoichiometry (UO2)4O(OH)6, formed from edge-sharing UO7 pentagonal bipyramids, interleaved with hydrogen-bonded water molecules. Three of the layer hydroxyl groups are linked through hydrogen bonding to single water molecules and the three remaining OH units form interactions with water molecules that each act as acceptors in two hydrogen bonds. One of the water molecules in the inter-layer region is disordered over two symmetry-related sites and forms hydrogen-bonded interactions only within the layer and with the uranyl O atoms. The relationship of the structure of meta-schoepite to that of schoepite is discussed in detail.
Supporting information
Data collection: DENZO (Otwinowski and Minor, 1997) COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski and Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski and Minor, 1997) and COLLECT (Hooft, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997).
Crystal data top
H16O20U4 | Dx = 4.989 Mg m−3 |
Mr = 1288.25 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pbcn | Cell parameters from 16680 reflections |
a = 14.6861 (4) Å | θ = 2.0–25.8° |
b = 13.9799 (3) Å | µ = 37.75 mm−1 |
c = 16.7063 (5) Å | T = 298 K |
V = 3429.97 (16) Å3 | Tablet, yellow |
Z = 8 | 0.03 × 0.02 × 0.01 mm |
F(000) = 4352 | |
Data collection top
Enraf Nonius KappaCCD area detector diffractometer | 3255 independent reflections |
Radiation source: Enraf Nonius FR591 rotating anode | 2106 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.090 |
Detector resolution: 9.091 pixels/mm pixels mm-1 | θmax = 25.8°, θmin = 2.0° |
ψ and θ scans to fill Ewald sphere | h = −16→17 |
Absorption correction: empirical (using intensity measurements) SORTAV (Blessing 1995, 1997)' | k = −12→17 |
Tmin = 0.519, Tmax = 0.778 | l = −20→20 |
16680 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.048 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.104 | H-atom parameters not defined |
S = 0.95 | w = 1/[σ2(Fo2) + (0.047P)2] where P = (Fo2 + 2Fc2)/3 |
3255 reflections | (Δ/σ)max = 0.001 |
119 parameters | Δρmax = 2.98 e Å−3 |
0 restraints | Δρmin = −2.84 e Å−3 |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor
wR and goodness of fit S are based on F2, conventional
R-factors R are based on F, with F set to zero for
negative F2. The threshold expression of F2 >
σ(F2) is used only for calculating R-factors(gt) etc.
and is not relevant to the choice of reflections for refinement.
R-factors based on F2 are statistically about twice as large
as those based on F, and R- factors based on ALL data will be
even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
U1 | 0.23453 (4) | 0.74724 (4) | 0.36301 (4) | 0.01561 (18) | |
U2 | 0.29656 (5) | 0.77012 (4) | 0.59321 (4) | 0.01655 (19) | |
U3 | 0.25426 (5) | 0.51155 (4) | 0.22973 (4) | 0.01706 (19) | |
U4 | 0.25432 (5) | 0.51460 (4) | 0.50131 (4) | 0.01630 (19) | |
O1 | 0.1802 (9) | 0.7479 (7) | 0.5935 (8) | 0.032 (3)* | |
O2 | 0.1438 (8) | 0.4529 (7) | 0.2244 (7) | 0.028 (3)* | |
O3 | 0.1293 (8) | 0.7449 (7) | 0.4127 (7) | 0.026 (3)* | |
O4 | 0.4167 (7) | 0.7849 (7) | 0.5914 (7) | 0.022 (3)* | |
O5 | 0.3642 (8) | 0.5633 (7) | 0.2359 (7) | 0.026 (3)* | |
O6 | 0.1416 (7) | 0.5579 (7) | 0.5179 (7) | 0.023 (3)* | |
O7 | 0.3385 (8) | 0.7524 (7) | 0.3101 (8) | 0.034 (3)* | |
O8 | 0.3692 (8) | 0.4724 (7) | 0.4845 (7) | 0.025 (3)* | |
O9 | 0.2652 (7) | 0.9236 (7) | 0.6079 (7) | 0.019 (3)* | |
O10 | 0.2028 (8) | 0.3615 (6) | 0.4591 (7) | 0.019 (3)* | |
O11 | 0.3125 (7) | 0.6719 (6) | 0.4737 (6) | 0.016 (3)* | |
O12 | 0.2152 (7) | 0.5667 (7) | 0.3635 (7) | 0.021 (3)* | |
O13 | 0.3121 (7) | 0.6007 (7) | 0.6270 (6) | 0.019 (3)* | |
O14 | 0.1846 (7) | 0.6852 (7) | 0.2342 (7) | 0.022 (3)* | |
O15 | 0.1863 (7) | 0.8888 (6) | 0.3066 (6) | 0.018 (3)* | |
O16 | 0.0000 | 0.7609 (12) | 0.2500 | 0.049 (5)* | |
O17 | 0.5015 (9) | 0.4409 (9) | 0.1386 (9) | 0.048 (4)* | |
O18 | −0.0253 (10) | 0.6223 (10) | 0.5870 (10) | 0.060 (4)* | |
O19 | 0.0314 (9) | 0.5621 (8) | 0.3391 (8) | 0.046 (4)* | |
O20 | −0.0119 (11) | 0.8529 (11) | 0.5792 (10) | 0.081 (5)* | |
O21 | 0.517 (3) | 0.758 (2) | 0.287 (2) | 0.096 (13)* | 0.50 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
U1 | 0.0283 (4) | 0.0136 (3) | 0.0049 (4) | −0.0004 (2) | −0.0002 (3) | −0.0006 (3) |
U2 | 0.0292 (4) | 0.0131 (3) | 0.0074 (3) | 0.0008 (3) | −0.0012 (3) | −0.0012 (3) |
U3 | 0.0320 (4) | 0.0135 (3) | 0.0057 (4) | 0.0002 (2) | −0.0001 (3) | 0.0001 (2) |
U4 | 0.0296 (4) | 0.0126 (3) | 0.0068 (4) | −0.0008 (2) | 0.0016 (3) | 0.0007 (2) |
Geometric parameters (Å, º) top
U1—O3 | 1.754 (12) | U3—O15iv | 2.315 (10) |
U1—O7 | 1.766 (13) | U3—O12 | 2.433 (11) |
U1—O15 | 2.303 (9) | U3—O13v | 2.475 (10) |
U1—O11 | 2.416 (10) | U3—O14 | 2.636 (10) |
U1—O14 | 2.433 (11) | U3—U4v | 3.8334 (9) |
U1—O10i | 2.445 (10) | U3—U2iii | 3.8827 (8) |
U1—O12 | 2.540 (9) | U4—O6 | 1.784 (11) |
U1—U2 | 3.9651 (9) | U4—O8 | 1.810 (11) |
U1—U3 | 3.9873 (8) | U4—O9iv | 2.207 (10) |
U1—U4 | 4.0001 (8) | U4—O10 | 2.378 (10) |
U2—O1 | 1.737 (13) | U4—O11 | 2.403 (9) |
U2—O4 | 1.777 (11) | U4—O12 | 2.481 (11) |
U2—O9 | 2.208 (9) | U4—O13 | 2.565 (11) |
U2—O11 | 2.434 (10) | U4—U2iv | 3.8205 (8) |
U2—O13 | 2.446 (9) | U4—U3vi | 3.8334 (9) |
U2—O14ii | 2.452 (11) | O9—U4i | 2.207 (10) |
U2—O10i | 2.578 (10) | O9—U3ii | 2.246 (11) |
U2—U4i | 3.8205 (8) | O10—U1iv | 2.445 (10) |
U2—U3ii | 3.8827 (8) | O10—U2iv | 2.578 (10) |
U2—U4 | 3.9373 (8) | O13—U3vi | 2.475 (10) |
U3—O5 | 1.773 (11) | O14—U2iii | 2.452 (11) |
U3—O2 | 1.820 (11) | O15—U3i | 2.315 (10) |
U3—O9iii | 2.246 (11) | O21—O21vii | 1.32 (7) |
| | | |
O3—U1—O7 | 177.8 (5) | O5—U3—O13v | 89.2 (4) |
O3—U1—O15 | 86.5 (4) | O2—U3—O13v | 89.2 (4) |
O7—U1—O15 | 91.5 (4) | O9iii—U3—O13v | 70.8 (3) |
O3—U1—O11 | 92.7 (5) | O15iv—U3—O13v | 77.6 (4) |
O7—U1—O11 | 89.5 (5) | O12—U3—O13v | 156.7 (3) |
O15—U1—O11 | 146.5 (3) | O5—U3—O14 | 88.6 (4) |
O3—U1—O14 | 98.4 (5) | O2—U3—O14 | 94.0 (4) |
O7—U1—O14 | 80.4 (5) | O9iii—U3—O14 | 66.7 (3) |
O15—U1—O14 | 81.4 (3) | O15iv—U3—O14 | 144.5 (3) |
O11—U1—O14 | 131.6 (3) | O12—U3—O14 | 65.8 (3) |
O3—U1—O10i | 91.9 (4) | O13v—U3—O14 | 137.5 (3) |
O7—U1—O10i | 88.6 (5) | O5—U3—U4v | 95.5 (4) |
O15—U1—O10i | 79.9 (3) | O2—U3—U4v | 84.8 (4) |
O11—U1—O10i | 66.6 (3) | O9iii—U3—U4v | 30.3 (2) |
O14—U1—O10i | 158.0 (3) | O15iv—U3—U4v | 118.8 (3) |
O3—U1—O12 | 83.2 (4) | O12—U3—U4v | 160.9 (2) |
O7—U1—O12 | 98.0 (4) | O13v—U3—U4v | 41.4 (2) |
O15—U1—O12 | 145.1 (4) | O14—U3—U4v | 96.7 (2) |
O11—U1—O12 | 67.5 (3) | O5—U3—U2iii | 83.6 (4) |
O14—U1—O12 | 67.4 (3) | O2—U3—U2iii | 98.9 (4) |
O10i—U1—O12 | 133.5 (3) | O9iii—U3—U2iii | 29.1 (2) |
O3—U1—U2 | 75.2 (4) | O15iv—U3—U2iii | 168.9 (3) |
O7—U1—U2 | 106.5 (4) | O12—U3—U2iii | 104.2 (2) |
O15—U1—U2 | 113.5 (3) | O13v—U3—U2iii | 99.0 (2) |
O11—U1—U2 | 35.3 (2) | O14—U3—U2iii | 38.5 (2) |
O14—U1—U2 | 162.9 (2) | U4v—U3—U2iii | 59.353 (15) |
O10i—U1—U2 | 39.1 (2) | O5—U3—U1 | 72.3 (3) |
O12—U1—U2 | 95.9 (3) | O2—U3—U1 | 109.5 (4) |
O3—U1—U3 | 108.2 (3) | O9iii—U3—U1 | 99.4 (2) |
O7—U1—U3 | 72.0 (3) | O15iv—U3—U1 | 109.3 (3) |
O15—U1—U3 | 120.2 (3) | O12—U3—U1 | 37.6 (2) |
O11—U1—U3 | 91.9 (2) | O13v—U3—U1 | 159.4 (2) |
O14—U1—U3 | 40.0 (2) | O14—U3—U1 | 36.4 (2) |
O10i—U1—U3 | 151.5 (2) | U4v—U3—U1 | 129.40 (2) |
O12—U1—U3 | 35.8 (3) | U2iii—U3—U1 | 70.394 (17) |
U2—U1—U3 | 126.269 (19) | O6—U4—O8 | 179.2 (5) |
O3—U1—U4 | 77.0 (3) | O6—U4—O9iv | 87.1 (4) |
O7—U1—U4 | 105.0 (3) | O8—U4—O9iv | 93.4 (4) |
O15—U1—U4 | 163.2 (3) | O6—U4—O10 | 93.2 (4) |
O11—U1—U4 | 33.8 (2) | O8—U4—O10 | 87.6 (4) |
O14—U1—U4 | 104.1 (2) | O9iv—U4—O10 | 71.3 (4) |
O10i—U1—U4 | 97.1 (2) | O6—U4—O11 | 92.8 (4) |
O12—U1—U4 | 36.7 (3) | O8—U4—O11 | 86.4 (4) |
U2—U1—U4 | 59.246 (14) | O9iv—U4—O11 | 136.7 (4) |
U3—U1—U4 | 69.231 (16) | O10—U4—O11 | 151.6 (4) |
O1—U2—O4 | 176.3 (5) | O6—U4—O12 | 80.2 (4) |
O1—U2—O9 | 88.2 (4) | O8—U4—O12 | 99.6 (5) |
O4—U2—O9 | 95.5 (4) | O9iv—U4—O12 | 152.5 (4) |
O1—U2—O11 | 89.7 (5) | O10—U4—O12 | 85.2 (3) |
O4—U2—O11 | 87.5 (4) | O11—U4—O12 | 68.6 (3) |
O9—U2—O11 | 131.3 (4) | O6—U4—O13 | 91.2 (4) |
O1—U2—O13 | 85.3 (4) | O8—U4—O13 | 88.4 (4) |
O4—U2—O13 | 91.4 (4) | O9iv—U4—O13 | 69.7 (3) |
O9—U2—O13 | 159.2 (4) | O10—U4—O13 | 140.4 (3) |
O11—U2—O13 | 68.5 (3) | O11—U4—O13 | 67.1 (3) |
O1—U2—O14ii | 98.9 (5) | O12—U4—O13 | 134.3 (3) |
O4—U2—O14ii | 82.8 (5) | O6—U4—U2iv | 93.4 (3) |
O9—U2—O14ii | 70.7 (4) | O8—U4—U2iv | 87.3 (3) |
O11—U2—O14ii | 157.0 (3) | O9iv—U4—U2iv | 30.1 (3) |
O13—U2—O14ii | 90.8 (3) | O10—U4—U2iv | 41.5 (3) |
O1—U2—O10i | 95.4 (5) | O11—U4—U2iv | 164.8 (3) |
O4—U2—O10i | 85.6 (4) | O12—U4—U2iv | 126.2 (2) |
O9—U2—O10i | 67.4 (3) | O13—U4—U2iv | 98.9 (2) |
O11—U2—O10i | 64.3 (3) | O6—U4—U3vi | 83.0 (4) |
O13—U2—O10i | 132.8 (3) | O8—U4—U3vi | 97.1 (4) |
O14ii—U2—O10i | 135.1 (3) | O9iv—U4—U3vi | 30.9 (3) |
O1—U2—U4i | 88.2 (3) | O10—U4—U3vi | 102.1 (3) |
O4—U2—U4i | 94.8 (3) | O11—U4—U3vi | 106.2 (2) |
O9—U2—U4i | 30.1 (3) | O12—U4—U3vi | 162.0 (2) |
O11—U2—U4i | 101.2 (2) | O13—U4—U3vi | 39.6 (2) |
O13—U2—U4i | 167.8 (3) | U2iv—U4—U3vi | 60.965 (16) |
O14ii—U2—U4i | 100.4 (2) | O6—U4—U2 | 77.2 (3) |
O10i—U2—U4i | 37.7 (2) | O8—U4—U2 | 102.1 (3) |
O1—U2—U3ii | 87.1 (4) | O9iv—U4—U2 | 103.2 (3) |
O4—U2—U3ii | 96.3 (3) | O10—U4—U2 | 169.3 (3) |
O9—U2—U3ii | 29.6 (3) | O11—U4—U2 | 35.8 (2) |
O11—U2—U3ii | 160.7 (2) | O12—U4—U2 | 97.6 (2) |
O13—U2—U3ii | 130.1 (3) | O13—U4—U2 | 37.1 (2) |
O14ii—U2—U3ii | 42.0 (2) | U2iv—U4—U2 | 133.30 (3) |
O10i—U2—U3ii | 97.0 (2) | U3vi—U4—U2 | 72.447 (18) |
U4i—U2—U3ii | 59.682 (16) | O6—U4—U1 | 75.3 (3) |
O1—U2—U4 | 71.6 (3) | O8—U4—U1 | 104.1 (3) |
O4—U2—U4 | 104.8 (3) | O9iv—U4—U1 | 157.7 (3) |
O9—U2—U4 | 153.1 (3) | O10—U4—U1 | 122.5 (3) |
O11—U2—U4 | 35.3 (2) | O11—U4—U1 | 34.0 (2) |
O13—U2—U4 | 39.3 (3) | O12—U4—U1 | 37.7 (2) |
O14ii—U2—U4 | 128.6 (2) | O13—U4—U1 | 96.6 (2) |
O10i—U2—U4 | 96.4 (2) | U2iv—U4—U1 | 160.95 (2) |
U4i—U2—U4 | 128.62 (2) | U3vi—U4—U1 | 130.73 (2) |
U3ii—U2—U4 | 155.78 (2) | U2—U4—U1 | 59.933 (15) |
O1—U2—U1 | 76.2 (4) | U4i—O9—U2 | 119.8 (5) |
O4—U2—U1 | 102.8 (4) | U4i—O9—U3ii | 118.8 (4) |
O9—U2—U1 | 98.0 (3) | U2—O9—U3ii | 121.3 (5) |
O11—U2—U1 | 35.0 (2) | U4—O10—U1iv | 131.5 (5) |
O13—U2—U1 | 99.6 (3) | U4—O10—U2iv | 100.8 (4) |
O14ii—U2—U1 | 168.0 (2) | U1iv—O10—U2iv | 104.2 (3) |
O10i—U2—U1 | 36.7 (2) | U4—O11—U1 | 112.2 (4) |
U4i—U2—U1 | 68.745 (17) | U4—O11—U2 | 108.9 (4) |
U3ii—U2—U1 | 126.09 (2) | U1—O11—U2 | 109.7 (4) |
U4—U2—U1 | 60.820 (15) | U3—O12—U4 | 134.8 (4) |
O5—U3—O2 | 177.3 (5) | U3—O12—U1 | 106.6 (4) |
O5—U3—O9iii | 90.2 (5) | U4—O12—U1 | 105.6 (4) |
O2—U3—O9iii | 91.4 (5) | U2—O13—U3vi | 137.9 (5) |
O5—U3—O15iv | 85.8 (4) | U2—O13—U4 | 103.6 (4) |
O2—U3—O15iv | 91.7 (4) | U3vi—O13—U4 | 99.0 (3) |
O9iii—U3—O15iv | 148.2 (4) | U1—O14—U2iii | 136.4 (4) |
O5—U3—O12 | 91.8 (5) | U1—O14—U3 | 103.7 (4) |
O2—U3—O12 | 88.7 (5) | U2iii—O14—U3 | 99.4 (4) |
O9iii—U3—O12 | 132.4 (3) | U1—O15—U3i | 138.4 (5) |
O15iv—U3—O12 | 79.3 (3) | | |
Symmetry codes: (i) −x+1/2, y+1/2, z; (ii) −x+1/2, −y+3/2, z+1/2; (iii) −x+1/2, −y+3/2, z−1/2; (iv) −x+1/2, y−1/2, z; (v) x, −y+1, z−1/2; (vi) x, −y+1, z+1/2; (vii) −x+1, y, −z+1/2. |
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