The industrial importance of the U-Al-Si system stems from the fact that during processing the Al-based alloy (containing Si as impurity), used for the cladding of U (fuel in nuclear reactors), undergoes heat treatment which stimulates diffusion between the fuel and the cladding. One of the possible ways to represent the ternary U-Al-Si phase diagram is the construction of an UAl3-USi3 quasi-binary phase diagram. On the one hand, since the UAl3 and USi3 phases are isostructural, an isomorphous phase diagram is expected; on the other hand, some researchers observed a miscibility gap at lower temperatures. During our study of the UAl3-USi3 quasi-binary phase diagram, a new stable U(Alx,Si1 - x)3 phase was identified. The structure of this phase was determined, using a combination of electron crystallography and powder X-ray diffraction methods, as tetragonal [I4/mmm (No.139) space group], with lattice parameters a = b = 8.347 (1), c = 16.808 (96) Å. Its unit cell has 64 atoms and it can be described as an ordered variant of the U(Al,Si)3 solid solution. A Bärnighausen tree was constructed using the original U(Al,Si)3 structure as an aristotype.
Supporting information
CCDC reference: 987736
Program(s) used to refine structure: SHELXL97 (Sheldrick, 1997).
Crystal data top
Al28Si20U16 | γ = 90° |
Mr = 5125.72 | V = 1171.1 (5) Å3 |
a = 8.3471 (10) Å | Z = 4 |
b = 8.3471 (10) Å | F(000) = 2116 |
c = 16.809 (6) Å | Dx = 7.268 Mg m−3 |
α = 90° | T = 293 K |
β = 90° | |
Data collection top
Radiation source: fine-focus sealed tube | Rint = 0.000 |
Graphite monochromator | θmax = 73.8°, θmin = 5.3° |
400 measured reflections | h = 0→10 |
400 independent reflections | k = 0→7 |
400 reflections with I > 2σ(I) | l = 0→20 |
Refinement top
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Primary atom site location: structure-invariant direct methods |
R[F2 > 2σ(F2)] = 0.032 | Secondary atom site location: difference Fourier map |
wR(F2) = 0.190 | w = 1/[σ2(Fo2) + (0.0936P)2] where P = (Fo2 + 2Fc2)/3 |
S = 2.03 | (Δ/σ)max < 0.001 |
400 reflections | Δρmax = 5.62 e Å−3 |
1 parameters | Δρmin = −3.91 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 | |
U1 | −0.2380 | 0.2380 | 0.1189 | 0.001* | |
Si1 | −0.2604 | 0.5000 | 0.0000 | 0.007* | |
Al1 | 0.0000 | 0.2477 | 0.2597 | 0.003* | |
Si2 | 0.0000 | 0.3178 | 0.0000 | 0.007* | |
Si3 | 0.0000 | 0.0000 | 0.1517 | 0.007* | |
Al3 | 0.5000 | 0.5000 | 0.1232 | 0.003* | |
Al4 | 0.0000 | 0.5000 | 0.1337 | 0.003* | |
Geometric parameters (Å, º) top
U1—Si3 | 2.8633 | Si2—Si1vi | 2.6528 |
U1—Si2i | 2.8952 | Si2—Al4 | 2.7133 |
U1—Si2 | 2.8952 | Si2—Al4vi | 2.7133 |
U1—Al4 | 2.9650 | Si2—U1viii | 2.8952 |
U1—Al4i | 2.9650 | Si2—U1xi | 2.8952 |
U1—Si1ii | 2.9681 | Si2—U1xiii | 2.8952 |
U1—Si1 | 2.9681 | Si3—Al1xi | 2.7516 |
U1—Al1iii | 2.9937 | Si3—Al1xiv | 2.7516 |
U1—Al1iv | 2.9937 | Si3—Al1i | 2.7516 |
U1—Al1 | 3.0918 | Si3—U1i | 2.8633 |
U1—Al1i | 3.0918 | Si3—U1xi | 2.8633 |
U1—Al3v | 3.0937 | Si3—U1xiv | 2.8633 |
Si1—Si2vi | 2.6528 | Al3—Al1xv | 2.8549 |
Si1—Si2 | 2.6528 | Al3—Al1xvi | 2.8549 |
Si1—Si1ii | 2.8283 | Al3—Al1xii | 2.8549 |
Si1—Si1vii | 2.8283 | Al3—Al1x | 2.8549 |
Si1—Al3vi | 2.8786 | Al3—Si1xiii | 2.8787 |
Si1—Al3v | 2.8787 | Al3—Si1vi | 2.8787 |
Si1—U1viii | 2.9681 | Al3—Si1xvii | 2.8787 |
Si1—U1vii | 2.9681 | Al3—Si1xviii | 2.8787 |
Si1—U1ix | 2.9681 | Al3—U1xi | 3.0937 |
Al1—Si3 | 2.7516 | Al3—U1xviii | 3.0937 |
Al1—Al4iii | 2.7649 | Al3—U1xvii | 3.0937 |
Al1—Al3x | 2.8549 | Al3—U1xix | 3.0937 |
Al1—Al1i | 2.9243 | Al4—Si2vi | 2.7133 |
Al1—Al1xi | 2.9243 | Al4—Al1xii | 2.7649 |
Al1—Al4 | 2.9871 | Al4—Al1iii | 2.7649 |
Al1—U1xii | 2.9937 | Al4—U1xix | 2.9650 |
Al1—U1iv | 2.9937 | Al4—U1xi | 2.9650 |
Al1—Al1xii | 2.9958 | Al4—U1vii | 2.9650 |
Al1—Al1iii | 2.9958 | Al4—Al1xix | 2.9871 |
Al1—U1xi | 3.0918 | | |
| | | |
Si3—U1—Si2i | 79.4 | U1xii—Al1—U1xi | 93.1 |
Si3—U1—Si2 | 79.4 | U1iv—Al1—U1xi | 173.0 |
Si2i—U1—Si2 | 80.8 | Al1xii—Al1—U1xi | 58.9 |
Si3—U1—Al4 | 91.8 | Al1iii—Al1—U1xi | 112.7 |
Si2i—U1—Al4 | 135.9 | U1—Al1—U1xi | 80.0 |
Si2—U1—Al4 | 55.1 | Si1vi—Si2—Si1 | 110.0 |
Si3—U1—Al4i | 91.8 | Si1vi—Si2—Al4 | 71.3 |
Si2i—U1—Al4i | 55.1 | Si1—Si2—Al4 | 71.3 |
Si2—U1—Al4i | 135.9 | Si1vi—Si2—Al4vi | 71.3 |
Al4—U1—Al4i | 168.9 | Si1—Si2—Al4vi | 71.3 |
Si3—U1—Si1ii | 133.2 | Al4—Si2—Al4vi | 111.8 |
Si2i—U1—Si1ii | 53.8 | Si1vi—Si2—U1viii | 134.0 |
Si2—U1—Si1ii | 91.5 | Si1—Si2—U1viii | 64.5 |
Al4—U1—Si1ii | 120.2 | Al4—Si2—U1viii | 134.5 |
Al4i—U1—Si1ii | 63.6 | Al4vi—Si2—U1viii | 63.7 |
Si3—U1—Si1 | 133.2 | Si1vi—Si2—U1xi | 64.5 |
Si2i—U1—Si1 | 91.5 | Si1—Si2—U1xi | 134.0 |
Si2—U1—Si1 | 53.8 | Al4—Si2—U1xi | 63.7 |
Al4—U1—Si1 | 63.6 | Al4vi—Si2—U1xi | 134.5 |
Al4i—U1—Si1 | 120.2 | U1viii—Si2—U1xi | 153.4 |
Si1ii—U1—Si1 | 56.9 | Si1vi—Si2—U1xiii | 64.5 |
Si3—U1—Al1iii | 113.8 | Si1—Si2—U1xiii | 134.0 |
Si2i—U1—Al1iii | 164.3 | Al4—Si2—U1xiii | 134.5 |
Si2—U1—Al1iii | 109.2 | Al4vi—Si2—U1xiii | 63.7 |
Al4—U1—Al1iii | 55.3 | U1viii—Si2—U1xiii | 86.7 |
Al4i—U1—Al1iii | 113.8 | U1xi—Si2—U1xiii | 87.3 |
Si1ii—U1—Al1iii | 112.6 | Si1vi—Si2—U1 | 134.0 |
Si1—U1—Al1iii | 85.3 | Si1—Si2—U1 | 64.5 |
Si3—U1—Al1iv | 113.8 | Al4—Si2—U1 | 63.7 |
Si2i—U1—Al1iv | 109.2 | Al4vi—Si2—U1 | 134.5 |
Si2—U1—Al1iv | 164.3 | U1viii—Si2—U1 | 87.3 |
Al4—U1—Al1iv | 113.8 | U1xi—Si2—U1 | 86.7 |
Al4i—U1—Al1iv | 55.3 | U1xiii—Si2—U1 | 153.4 |
Si1ii—U1—Al1iv | 85.3 | Al1xi—Si3—Al1 | 64.2 |
Si1—U1—Al1iv | 112.6 | Al1xi—Si3—Al1xiv | 64.2 |
Al1iii—U1—Al1iv | 58.5 | Al1—Si3—Al1xiv | 97.4 |
Si3—U1—Al1 | 54.9 | Al1xi—Si3—Al1i | 97.4 |
Si2i—U1—Al1 | 134.0 | Al1—Si3—Al1i | 64.2 |
Si2—U1—Al1 | 94.7 | Al1xiv—Si3—Al1i | 64.2 |
Al4—U1—Al1 | 59.1 | Al1xi—Si3—U1i | 130.4 |
Al4i—U1—Al1 | 115.3 | Al1—Si3—U1i | 130.4 |
Si1ii—U1—Al1 | 170.8 | Al1xiv—Si3—U1i | 66.8 |
Si1—U1—Al1 | 122.5 | Al1i—Si3—U1i | 66.8 |
Al1iii—U1—Al1 | 59.0 | Al1xi—Si3—U1xi | 66.8 |
Al1iv—U1—Al1 | 86.9 | Al1—Si3—U1xi | 66.8 |
Si3—U1—Al1i | 54.9 | Al1xiv—Si3—U1xi | 130.4 |
Si2i—U1—Al1i | 94.7 | Al1i—Si3—U1xi | 130.4 |
Si2—U1—Al1i | 134.0 | U1i—Si3—U1xi | 157.8 |
Al4—U1—Al1i | 115.3 | Al1xi—Si3—U1xiv | 66.8 |
Al4i—U1—Al1i | 59.1 | Al1—Si3—U1xiv | 130.4 |
Si1ii—U1—Al1i | 122.5 | Al1xiv—Si3—U1xiv | 66.8 |
Si1—U1—Al1i | 170.8 | Al1i—Si3—U1xiv | 130.4 |
Al1iii—U1—Al1i | 86.9 | U1i—Si3—U1xiv | 87.9 |
Al1iv—U1—Al1i | 59.0 | U1xi—Si3—U1xiv | 87.9 |
Al1—U1—Al1i | 56.4 | Al1xi—Si3—U1 | 130.4 |
Si3—U1—Al3v | 167.5 | Al1—Si3—U1 | 66.8 |
Si2i—U1—Al3v | 109.8 | Al1xiv—Si3—U1 | 130.4 |
Si2—U1—Al3v | 109.8 | Al1i—Si3—U1 | 66.8 |
Al4—U1—Al3v | 87.1 | U1i—Si3—U1 | 87.9 |
Al4i—U1—Al3v | 87.1 | U1xi—Si3—U1 | 87.9 |
Si1ii—U1—Al3v | 56.7 | U1xiv—Si3—U1 | 157.8 |
Si1—U1—Al3v | 56.7 | Al1xv—Al3—Al1xvi | 61.6 |
Al1iii—U1—Al3v | 55.9 | Al1xv—Al3—Al1xii | 61.6 |
Al1iv—U1—Al3v | 55.9 | Al1xvi—Al3—Al1xii | 92.8 |
Al1—U1—Al3v | 114.7 | Al1xv—Al3—Al1x | 92.8 |
Al1i—U1—Al3v | 114.7 | Al1xvi—Al3—Al1x | 61.6 |
Si2vi—Si1—Si2 | 70.0 | Al1xii—Al3—Al1x | 61.6 |
Si2vi—Si1—Si1ii | 170.0 | Al1xv—Al3—Si1xiii | 177.6 |
Si2—Si1—Si1ii | 100.0 | Al1xvi—Al3—Si1xiii | 119.7 |
Si2vi—Si1—Si1vii | 100.0 | Al1xii—Al3—Si1xiii | 119.7 |
Si2—Si1—Si1vii | 170.0 | Al1x—Al3—Si1xiii | 89.6 |
Si1ii—Si1—Si1vii | 90.0 | Al1xv—Al3—Si1vi | 119.7 |
Si2vi—Si1—Al3vi | 124.7 | Al1xvi—Al3—Si1vi | 177.6 |
Si2—Si1—Al3vi | 124.7 | Al1xii—Al3—Si1vi | 89.6 |
Si1ii—Si1—Al3vi | 60.6 | Al1x—Al3—Si1vi | 119.7 |
Si1vii—Si1—Al3vi | 60.6 | Si1xiii—Al3—Si1vi | 58.8 |
Si2vi—Si1—Al3v | 124.7 | Al1xv—Al3—Si1xvii | 119.7 |
Si2—Si1—Al3v | 124.7 | Al1xvi—Al3—Si1xvii | 89.6 |
Si1ii—Si1—Al3v | 60.6 | Al1xii—Al3—Si1xvii | 177.6 |
Si1vii—Si1—Al3v | 60.6 | Al1x—Al3—Si1xvii | 119.7 |
Al3vi—Si1—Al3v | 92.0 | Si1xiii—Al3—Si1xvii | 58.8 |
Si2vi—Si1—U1viii | 111.8 | Si1vi—Al3—Si1xvii | 88.0 |
Si2—Si1—U1viii | 61.7 | Al1xv—Al3—Si1xviii | 89.6 |
Si1ii—Si1—U1viii | 61.5 | Al1xvi—Al3—Si1xviii | 119.7 |
Si1vii—Si1—U1viii | 124.4 | Al1xii—Al3—Si1xviii | 119.7 |
Al3vi—Si1—U1viii | 63.9 | Al1x—Al3—Si1xviii | 177.6 |
Al3v—Si1—U1viii | 121.9 | Si1xiii—Al3—Si1xviii | 88.0 |
Si2vi—Si1—U1vii | 61.7 | Si1vi—Al3—Si1xviii | 58.8 |
Si2—Si1—U1vii | 111.8 | Si1xvii—Al3—Si1xviii | 58.8 |
Si1ii—Si1—U1vii | 124.4 | Al1xv—Al3—U1xi | 121.9 |
Si1vii—Si1—U1vii | 61.5 | Al1xvi—Al3—U1xi | 121.9 |
Al3vi—Si1—U1vii | 121.9 | Al1xii—Al3—U1xi | 60.3 |
Al3v—Si1—U1vii | 63.9 | Al1x—Al3—U1xi | 60.3 |
U1viii—Si1—U1vii | 172.8 | Si1xiii—Al3—U1xi | 59.5 |
Si2vi—Si1—U1 | 111.8 | Si1vi—Al3—U1xi | 59.5 |
Si2—Si1—U1 | 61.7 | Si1xvii—Al3—U1xi | 118.3 |
Si1ii—Si1—U1 | 61.5 | Si1xviii—Al3—U1xi | 118.3 |
Si1vii—Si1—U1 | 124.4 | Al1xv—Al3—U1xviii | 60.3 |
Al3vi—Si1—U1 | 121.9 | Al1xvi—Al3—U1xviii | 60.3 |
Al3v—Si1—U1 | 63.9 | Al1xii—Al3—U1xviii | 121.9 |
U1viii—Si1—U1 | 84.6 | Al1x—Al3—U1xviii | 121.9 |
U1vii—Si1—U1 | 94.9 | Si1xiii—Al3—U1xviii | 118.3 |
Si2vi—Si1—U1ix | 61.7 | Si1vi—Al3—U1xviii | 118.3 |
Si2—Si1—U1ix | 111.8 | Si1xvii—Al3—U1xviii | 59.5 |
Si1ii—Si1—U1ix | 124.4 | Si1xviii—Al3—U1xviii | 59.5 |
Si1vii—Si1—U1ix | 61.5 | U1xi—Al3—U1xviii | 177.3 |
Al3vi—Si1—U1ix | 63.9 | Al1xv—Al3—U1xvii | 121.9 |
Al3v—Si1—U1ix | 121.9 | Al1xvi—Al3—U1xvii | 60.3 |
U1viii—Si1—U1ix | 94.9 | Al1xii—Al3—U1xvii | 121.9 |
U1vii—Si1—U1ix | 84.6 | Al1x—Al3—U1xvii | 60.3 |
U1—Si1—U1ix | 172.8 | Si1xiii—Al3—U1xvii | 59.5 |
Si3—Al1—Al4iii | 179.1 | Si1vi—Al3—U1xvii | 118.3 |
Si3—Al1—Al3x | 84.9 | Si1xvii—Al3—U1xvii | 59.5 |
Al4iii—Al1—Al3x | 96.0 | Si1xviii—Al3—U1xvii | 118.3 |
Si3—Al1—Al1i | 57.9 | U1xi—Al3—U1xvii | 90.0 |
Al4iii—Al1—Al1i | 122.6 | U1xviii—Al3—U1xvii | 90.0 |
Al3x—Al1—Al1i | 59.2 | Al1xv—Al3—U1xix | 60.3 |
Si3—Al1—Al1xi | 57.9 | Al1xvi—Al3—U1xix | 121.9 |
Al4iii—Al1—Al1xi | 122.6 | Al1xii—Al3—U1xix | 60.3 |
Al3x—Al1—Al1xi | 59.2 | Al1x—Al3—U1xix | 121.9 |
Al1i—Al1—Al1xi | 90.0 | Si1xiii—Al3—U1xix | 118.3 |
Si3—Al1—Al4 | 93.5 | Si1vi—Al3—U1xix | 59.5 |
Al4iii—Al1—Al4 | 85.6 | Si1xvii—Al3—U1xix | 118.3 |
Al3x—Al1—Al4 | 178.4 | Si1xviii—Al3—U1xix | 59.5 |
Al1i—Al1—Al4 | 119.9 | U1xi—Al3—U1xix | 90.0 |
Al1xi—Al1—Al4 | 119.9 | U1xviii—Al3—U1xix | 90.0 |
Si3—Al1—U1xii | 118.7 | U1xvii—Al3—U1xix | 177.3 |
Al4iii—Al1—U1xii | 61.8 | Si2—Al4—Si2vi | 68.2 |
Al3x—Al1—U1xii | 63.8 | Si2—Al4—Al1xii | 122.5 |
Al1i—Al1—U1xii | 123.0 | Si2vi—Al4—Al1xii | 122.5 |
Al1xi—Al1—U1xii | 60.8 | Si2—Al4—Al1iii | 122.5 |
Al4—Al1—U1xii | 117.1 | Si2vi—Al4—Al1iii | 122.5 |
Si3—Al1—U1iv | 118.7 | Al1xii—Al4—Al1iii | 99.2 |
Al4iii—Al1—U1iv | 61.8 | Si2—Al4—U1 | 61.1 |
Al3x—Al1—U1iv | 63.8 | Si2vi—Al4—U1 | 110.1 |
Al1i—Al1—U1iv | 60.8 | Al1xii—Al4—U1 | 124.4 |
Al1xi—Al1—U1iv | 123.0 | Al1iii—Al4—U1 | 62.9 |
Al4—Al1—U1iv | 117.1 | Si2—Al4—U1xix | 110.1 |
U1xii—Al1—U1iv | 93.9 | Si2vi—Al4—U1xix | 61.1 |
Si3—Al1—Al1xii | 117.1 | Al1xii—Al4—U1xix | 62.9 |
Al4iii—Al1—Al1xii | 62.3 | Al1iii—Al4—U1xix | 124.4 |
Al3x—Al1—Al1xii | 125.8 | U1—Al4—U1xix | 170.4 |
Al1i—Al1—Al1xii | 173.7 | Si2—Al4—U1xi | 61.1 |
Al1xi—Al1—Al1xii | 90.0 | Si2vi—Al4—U1xi | 110.1 |
Al4—Al1—Al1xii | 55.1 | Al1xii—Al4—U1xi | 62.9 |
U1xii—Al1—Al1xii | 62.2 | Al1iii—Al4—U1xi | 124.4 |
U1iv—Al1—Al1xii | 124.0 | U1—Al4—U1xi | 84.1 |
Si3—Al1—Al1iii | 117.1 | U1xix—Al4—U1xi | 95.1 |
Al4iii—Al1—Al1iii | 62.3 | Si2—Al4—U1vii | 110.1 |
Al3x—Al1—Al1iii | 125.8 | Si2vi—Al4—U1vii | 61.1 |
Al1i—Al1—Al1iii | 90.0 | Al1xii—Al4—U1vii | 124.4 |
Al1xi—Al1—Al1iii | 173.7 | Al1iii—Al4—U1vii | 62.9 |
Al4—Al1—Al1iii | 55.1 | U1—Al4—U1vii | 95.1 |
U1xii—Al1—Al1iii | 124.0 | U1xix—Al4—U1vii | 84.1 |
U1iv—Al1—Al1iii | 62.2 | U1xi—Al4—U1vii | 170.4 |
Al1xii—Al1—Al1iii | 89.3 | Si2—Al4—Al1xix | 169.3 |
Si3—Al1—U1 | 58.3 | Si2vi—Al4—Al1xix | 101.1 |
Al4iii—Al1—U1 | 121.1 | Al1xii—Al4—Al1xix | 62.6 |
Al3x—Al1—U1 | 120.6 | Al1iii—Al4—Al1xix | 62.6 |
Al1i—Al1—U1 | 61.8 | U1—Al4—Al1xix | 125.4 |
Al1xi—Al1—U1 | 115.8 | U1xix—Al4—Al1xix | 62.6 |
Al4—Al1—U1 | 58.4 | U1xi—Al4—Al1xix | 125.4 |
U1xii—Al1—U1 | 173.0 | U1vii—Al4—Al1xix | 62.6 |
U1iv—Al1—U1 | 93.1 | Si2—Al4—Al1 | 101.1 |
Al1xii—Al1—U1 | 112.7 | Si2vi—Al4—Al1 | 169.3 |
Al1iii—Al1—U1 | 58.9 | Al1xii—Al4—Al1 | 62.6 |
Si3—Al1—U1xi | 58.3 | Al1iii—Al4—Al1 | 62.6 |
Al4iii—Al1—U1xi | 121.1 | U1—Al4—Al1 | 62.6 |
Al3x—Al1—U1xi | 120.6 | U1xix—Al4—Al1 | 125.4 |
Al1i—Al1—U1xi | 115.8 | U1xi—Al4—Al1 | 62.6 |
Al1xi—Al1—U1xi | 61.8 | U1vii—Al4—Al1 | 125.4 |
Al4—Al1—U1xi | 58.4 | Al1xix—Al4—Al1 | 89.7 |
Symmetry codes: (i) −y, x, z; (ii) y−1, −x, −z; (iii) y−1/2, −x+1/2, −z+1/2; (iv) −x−1/2, −y+1/2, −z+1/2; (v) x−1, y, z; (vi) −x, −y+1, −z; (vii) −y, x+1, z; (viii) x, y, −z; (ix) −y, x+1, −z; (x) −x+1/2, −y+1/2, −z+1/2; (xi) y, −x, z; (xii) −y+1/2, x+1/2, −z+1/2; (xiii) y, −x, −z; (xiv) −x, −y, z; (xv) x+1/2, y+1/2, −z+1/2; (xvi) y+1/2, −x+1/2, −z+1/2; (xvii) x+1, y, z; (xviii) −y+1, x+1, z; (xix) −x, −y+1, z. |