Incommensurate structure of Ca2Al2O5 at high temperatures - structure investigation and Raman spectroscopy
Authors:Lazic, Biljana; Kruger, Hannes; Kahlenberg, Volker; Konzett, Jurgen; Kaindl, Reinhard
Journal:Acta Crystallographica, Section B 64 417-425 (2008)
DOI:https://doi.org/10.1107/S0108768108016029
B-IncStrDB ID: YqkusYLGDGZ Entry date: 2022-01-24 Last revision: 2022-01-24
I
Chemical data
Structural Formula Sum: Ca2 Al2 O5 [ Help ]
Formula weight: 214.12 Da [ Help ]
Crystallographic data and experimental details
Crystal system: orthorhombic [ Help ]
Superspace group name: Imma(00γ)s00 [ Help ]
Symmetry operations of the superspace group: (Show/hide table) [ Help ]
| Operation code | Operation in algebraic form |
|---|---|
| 1 | x1,x2,x3,x4 |
| 2 | -x1,x2,x3,1/2+x4 |
| 3 | x1,1/2-x2,x3,x4 |
| 4 | -x1,1/2-x2,x3,1/2+x4 |
| 5 | -x1,-x2,-x3,-x4 |
| 6 | x1,-x2,-x3,1/2-x4 |
| 7 | -x1,1/2+x2,-x3,-x4 |
| 8 | x1,1/2+x2,-x3,1/2-x4 |
| 9 | 1/2+x1,1/2+x2,1/2+x3,x4 |
| 10 | 1/2-x1,1/2+x2,1/2+x3,1/2+x4 |
| 11 | 1/2+x1,-x2,1/2+x3,x4 |
| 12 | 1/2-x1,-x2,1/2+x3,1/2+x4 |
| 13 | 1/2-x1,1/2-x2,1/2-x3,-x4 |
| 14 | 1/2+x1,1/2-x2,1/2-x3,1/2-x4 |
| 15 | 1/2-x1,x2,1/2-x3,-x4 |
| 16 | 1/2+x1,x2,1/2-x3,1/2-x4 |
a: 5.2699(5) Å [ Help ]
b: 14.6984(15) Å [ Help ]
c: 5.4196(5) Å [ Help ]
α: 90.00 ° [ Help ]
β: 90.00 ° [ Help ]
γ: 90.00 ° [ Help ]
Volume: 419.80(7) Å3 [ Help ]
Z: 4 [ Help ]
Cell determination reflection Nb.: 3428 [ Help ]
θ(min) for cell determination: 2.77 ° [ Help ]
θ(max) for cell determination: 30.82 ° [ Help ]
Cell measurement temperature: 1090(10) K [ Help ]
Modulation dimension: 1 [ Help ]
Measured independent wave vectors: (Show/hide table) [ Help ]
| Wave vector id | q_x | q_y | q_z |
|---|---|---|---|
| 1 | 0.00000 | 0.00000 | 0.595(1) |
μ: 3.04 mm-1 [ Help ]
Absorption correction type: integration [ Help ]
Minimum transmission factor: 0.7938 [ Help ]
Maximum transmission factor: 0.8340 [ Help ]
Refinement details
Total nb. of reflections: 848 [ Help ]
Nb. of observed reflections: 680 [ Help ]
Intense reflections threshold: I>3σ(I) [ Help ]
Refinement based on: F [ Help ]
R(all): 0.0695 [ Help ]
R(obs): 0.0546 [ Help ]
wR(obs): 0.0659 [ Help ]
wR(all): 0.0677 [ Help ]
S(all): 3.52 [ Help ]
Nb. of reflections: 848 [ Help ]
Nb. of parameters: 43 [ Help ]
Weighting scheme: sigma [ Help ]
Weighting scheme remarks: w=1/(σ2(F)+0.0001F2) [ Help ]
Δ/σ(max): 0.0001 [ Help ]
Δ/σ(mean): 0.0000 [ Help ]
Δρ(max): 1.16 e_Å-3 [ Help ]
Δρ(min): -1.04 e_Å-3 [ Help ]
Extinction method: none [ Help ]
Structural Information
Average Structure: (Show/hide table) [ Help ]
| Atom symbol | Atom site label | x | y | z | Uiso/equiv | ADP type | Coords from (d)iffraction or (c)alculated | Coords restraints or constraints | Occupancy | Disordered cluster | Disordered group |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Al | Al1 | 0 | 0 | 0.5 | 0.0267(4) | Uani | d | . | 1 | . | . |
| Al | Al2 | 0.9527(3) | 0.25 | 0.5744(3) | 0.0224(4) | Uani | d | . | 0.5 | . | . |
| Ca | Ca1 | 0 | 0.10837(5) | 0.02219(13) | 0.0276(2) | Uani | d | . | 1 | . | . |
| O | O1 | 0.75 | 0.00922(14) | 0.75 | 0.0224(6) | Uani | d | . | 1 | . | . |
| O | O2 | 0 | 0.14308(17) | 0.4457(6) | 0.0325(8) | Uani | d | . | 1 | . | . |
| O | O3 | 0.3830(6) | 0.25 | 0.6372(8) | 0.0274(11) | Uani | d | . | 0.5 | . | . |
ADP components: (Show/hide table) [ Help ]
| Atom site label | U11 | U22 | U33 | U12 | U13 | U23 | Atom site symbol |
|---|---|---|---|---|---|---|---|
| Al1 | 0.0159(6) | 0.0471(9) | 0.0173(7) | 0 | 0 | -0.0008(5) | Al |
| Al2 | 0.0278(7) | 0.0191(7) | 0.0204(7) | 0 | 0.0015(5) | 0 | Al |
| Ca1 | 0.0325(4) | 0.0230(4) | 0.0273(4) | 0 | 0 | 0.0010(2) | Ca |
| O1 | 0.0185(9) | 0.0286(10) | 0.0201(11) | 0 | 0.0031(7) | 0 | O |
| O2 | 0.0379(14) | 0.0262(13) | 0.0333(14) | 0 | 0 | -0.0081(10) | O |
| O3 | 0.0252(16) | 0.0299(19) | 0.027(2) | 0 | -0.0045(13) | 0 | O |
Fourier Wave Vectors (explicit: q_x,q_y,q_z or coefficients: q_1,q_2,...): (Show/hide table) [ Help ]
| Wave vector code | q_x | q_z |
|---|---|---|
| 1 | 0.00000 | 0.595 |
Definition of the displacive (translational) Fourier series: (Show/hide table) [ Help ]
| Modulation code | Atom site label | Displacement axis | Wave vector code |
|---|---|---|---|
| Al1x1 | Al1 | x | 1 |
| Al1y1 | Al1 | y | 1 |
| Al1z1 | Al1 | z | 1 |
| Ca1x1 | Ca1 | x | 1 |
| Ca1y1 | Ca1 | y | 1 |
| Ca1z1 | Ca1 | z | 1 |
| O1x1 | O1 | x | 1 |
| O1y1 | O1 | y | 1 |
| O1z1 | O1 | z | 1 |
| O2x1 | O2 | x | 1 |
| O2y1 | O2 | y | 1 |
| O2z1 | O2 | z | 1 |
Displacive (translational) Fourier coefficients: (Show/hide table) [ Help ]
| Modulation code | Cosine coefficient | Sine coefficient |
|---|---|---|
| Al1x1 | 0 | -0.0017(3) |
| Al1y1 | 0 | 0 |
| Al1z1 | 0 | 0 |
| Ca1x1 | 0.0064(2) | -0.00492(19) |
| Ca1y1 | 0 | 0 |
| Ca1z1 | 0 | 0 |
| O1x1 | 0 | -0.0012(6) |
| O1y1 | 0.0009(2) | 0 |
| O1z1 | 0 | -0.0004(7) |
| O2x1 | 0.0117(7) | 0.0036(7) |
| O2y1 | 0 | 0 |
| O2z1 | 0 | 0 |
Occupation crenel coefficients: (Show/hide table) [ Help ]
| Atom site label | Center (x0) | Width |
|---|---|---|
| Al2 | 0.1471(13) | 0.5 |
| O3 | 0.6844(13) | 0.5 |