Ordered vacancy distribution in 2/1 mullite: A superspace model

Authors:

Klar, Paul Benjamin; de la Pinta, Noelia; Lopez, Gabriel Alejandro; Etxebarria, Inigo; Breczweski, Tomasz; Madariaga, Gotzon

Journal:

Acta Crystallographica, Section B 73 377-388 (2017)

DOI:

https://doi.org/10.1107/S2052520617001652

B-IncStrDB ID: 13172EtfBj9 Entry date: 2017-06-06 Last revision: 2021-12-12

I

Chemical data


Common Name: Mullite [ Help ]

Formula moiety: 2.1(Al2 O3), (Si O2) [ Help ]

Structural Formula Sum: Al4.847 O9.577 Si1.153 [ Help ]

Formula weight: 316.4 Da [ Help ]

Compound Source: Sigma Aldrich [ Help ]

Crystallographic data and experimental details


Crystal system: orthorhombic [ Help ]

Superspace group name: Pbam(α01/2)0ss [ Help ]

Symmetry operations of the superspace group: [ Help ]

Operation code Operation in algebraic form
1 x1,x2,x3,x4
2 -x1,-x2,x3,x3-x4+1/2
3 -x1+1/2,x2+1/2,-x3,-x4+1/2
4 x1+1/2,-x2+1/2,-x3,-x3+x4
5 -x1,-x2,-x3,-x4
6 x1,x2,-x3,-x3+x4+1/2
7 x1+1/2,-x2+1/2,x3,x4+1/2
8 -x1+1/2,x2+1/2,x3,x3-x4

a: 7.5817(6) Å [ Help ]

b: 7.6752(7) Å [ Help ]

c: 2.8843(3) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 167.84(3) Å3 [ Help ]

Modulation dimension: 1 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0.300100 0.000000 0.500000

Z: 1 [ Help ]

Cell determination reflection Nb.: 2808 [ Help ]

θ(min) for cell determination: 3.77 ° [ Help ]

θ(max) for cell determination: 39.54 ° [ Help ]

Cell measurement temperature: 293 K [ Help ]

μ: 1.06 mm-1 [ Help ]

Absorption correction type: numerical [ Help ]

Absorption correction remarks: STOE X-Red32 [ Help ]

Minimum transmission factor: 0.9650 [ Help ]

Maximum transmission factor: 0.9810 [ Help ]

Refinement details


Total nb. of reflections: 864 [ Help ]

Nb. of observed reflections: 516 [ Help ]

Intense reflections threshold: I>3σ(I) [ Help ]

Refinement based on: Fsqd [ Help ]

R(obs): 0.0354 [ Help ]

wR(obs): 0.0886 [ Help ]

R(all): 0.0629 [ Help ]

wR(all): 0.1115 [ Help ]

S(all): 0.98 [ Help ]

S(obs): 1.03 [ Help ]

Nb. of reflections: 864 [ Help ]

Nb. of parameters: 52 [ Help ]

Number of constraints: 12 [ Help ]

Weighting scheme: sigma [ Help ]

Weighting scheme remarks: w=1/(σ2(I)+0.0049000001I2) [ Help ]

Refinement of hydrogen atoms: constr [ Help ]

Δ/σ(max): 0.0008 [ Help ]

Δ/σ(mean): 0.0001 [ Help ]

Δρ(max): 1.18 e_Å-3 [ Help ]

Δρ(min): -1.02 e_Å-3 [ Help ]

Extinction method: none [ Help ]

Structural Information


Average Structure: [ Help ]

Atom site label Atom symbol x y z ADP type Uiso/equiv Symmetry multiplicity Occupancy Coords from (d)iffraction or (c)alculated Coords restraints or constraints
Al1 Al 0 0 0 Uani 0.00645(18) 2 0.25 d ?
Al2 Al 0.1492(2) 0.3407(2) 0.5 Uani 0.00716(16) 4 0.317127 d ?
Si2 Si 0.1492(2) 0.3407(2) 0.5 Uani 0.00716(16) 4 0.182873 d ?
Al3 Al 0.2629(3) 0.2050(3) 0.5 Uani 0.0068(4) 4 0.5 d ?
O1 O 0.35872(15) 0.42222(18) 0.5 Uani 0.0082(6) 4 0.5 d ?
O2 O 0.12751(16) 0.21796(17) 0 Uani 0.0132(4) 4 0.5 d ?
O3a O 0 0.5 0.5 Uani 0.0195(18) 2 0.25 d ?
O3b O 0 0.5 0.5 Uani 0.0195(18) 4 0.5 d ?
O4 O 0.4514(9) 0.0492(8) 0.5 Uani 0.0112(14) 4 0.5 d ?

ADP components: [ Help ]

Atom site label Atom site symbol U11 U22 U33 U12 U13 U23
Al1 Al 0.0084(2) 0.0065(2) 0.0044(4) 0.00029(17) 0 0
Al2 Al 0.0065(3) 0.0071(3) 0.0079(2) -0.0014(2) 0 0
Si2 Si 0.0065(3) 0.0071(3) 0.0079(2) -0.0014(2) 0 0
Al3 Al 0.0059(7) 0.0078(8) 0.0066(8) 0.0010(6) 0 0
O1 O 0.0113(8) 0.0073(15) 0.0059(4) -0.0011(9) 0 0
O2 O 0.0164(5) 0.0141(4) 0.0091(9) -0.0069(4) 0 0
O3a O 0.018(3) 0.015(3) 0.025(3) 0.002(2) 0 0
O3b O 0.018(3) 0.015(3) 0.025(3) 0.002(2) 0 0
O4 O 0.012(3) 0.008(3) 0.015(2) 0.0014(18) 0 0

Fourier Wave Vectors (explicit: q_x,q_y,q_z or coefficients: q_1,q_2,...): [ Help ]

Wave vector code q_1
1 1

Occupation crenel coefficients: [ Help ]

Atom site label Center (x0) Width
Al2 0.04477(7) 0.7883
Si2 0.04477(7) 0.788(2)
Al3 0.57888(12) 0.212(2)
O3a 0 0.088(2)
O3b 0.325(2) 0.138(4)
O4 0.6355(3) 0.212(2)

Definition of the displacive (translational) Fourier series: [ Help ]

Modulation code Atom site label Displacement axis Wave vector code
Al1x1 Al1 x 1
Al1y1 Al1 y 1
Al1z1 Al1 z 1
Al1x2 Al2 x 1
Al1y2 Al2 y 1
Al1z2 Al2 z 1
Si2x1 Si2 x 1
Si2y1 Si2 y 1
Si2z1 Si2 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: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Al1x1 0 0
Al1y1 0 0
Al1z1 0 -0.020(2)
Al1x2 0.0011(8) -0.0041(5)
Al1y2 -0.0015(9) -0.0057(6)
Al1z2 0 0
Si2x1 0.0011(8) -0.0041(5)
Si2y1 -0.0015(9) -0.0057(6)
Si2z1 0 0
O1x1 -0.0064(11) -0.0094(11)
O1y1 0.0165(10) 0.0099(12)
O1z1 0 0
O2x1 0 0
O2y1 0 0
O2z1 -0.025(3) -0.013(3)

II

Chemical data


Common Name: 2/1 Mullite [ Help ]

Formula moiety: (Al2 O8),(Si0.8 O0.4),(Al0.4 Si0.4 O0.4),(Al2.4 O0.8) [ Help ]

Structural Formula Sum: Al4.8 O9.6 Si1.2 [ Help ]

Crystallographic data and experimental details


a: 75.8170(6) Å [ Help ]

b: 7.6752(7) Å [ Help ]

c: 5.7686(3) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 3356.8(4) Å3 [ Help ]

Z: 10 [ Help ]

Crystal system: orthorhombic [ Help ]

Space group name (H-M): B b 21 m [ Help ]

Space group nb.: 36 [ Help ]

Symmetry operations of the space group: [ Help ]

Operation code Operation in algebraic form
1 x, y, z
2 -x, y+1/2, -z
3 -x, y+1/2, z
4 x, y, -z
5 x+1/2, y, z+1/2
6 -x+1/2, y+1/2, -z+1/2
7 -x+1/2, y+1/2, z+1/2
8 x+1/2, y, -z+1/2

Refinement details


Structural Information


Average Structure: [ Help ]

Atom site label Occupancy x y z ADP type Uiso/equiv Atom symbol
Al11 1.0 0.025000 0.500000 0.245409 Uiso 0.006463 Al
Al12 1.0 0.075000 0.000000 0.259987 Uiso 0.006463 Al
Al13 1.0 0.125000 0.500000 0.242850 Uiso 0.006463 Al
Al14 1.0 0.175000 0.000000 0.248418 Uiso 0.006463 Al
Al15 1.0 0.225000 0.500000 0.259009 Uiso 0.006463 Al
Al21 1.0 0.010357 0.836560 0.000000 Uiso 0.007123 Al
Al22 1.0 0.040259 0.156979 0.000000 Uiso 0.007123 Al
Al23 1.0 0.109786 0.841865 0.000000 Uiso 0.007123 Al
Al24 1.0 0.139725 0.163262 0.000000 Uiso 0.007123 Al
Al25 1.0 0.160411 0.663215 0.000000 Uiso 0.007123 Al
Al26 1.0 0.190271 0.343947 0.000000 Uiso 0.007123 Al
Al27 1.0 0.259860 0.659408 0.000000 Uiso 0.007123 Al
Al28 1.0 0.289826 0.337300 0.000000 Uiso 0.007123 Al
Al29 1.0 0.389624 0.339473 0.000000 Uiso 0.007123 Al
Al210 1.0 0.460422 0.661683 0.000000 Uiso 0.007123 Al
Si21 1.0 0.310434 0.837391 0.000000 Uiso 0.007123 Si
Si22 1.0 0.340249 0.155447 0.000000 Uiso 0.007123 Si
Si23 1.0 0.359888 0.655400 0.000000 Uiso 0.007123 Si
Si24 1.0 0.409956 0.839326 0.000000 Uiso 0.007123 Si
Si25 1.0 0.439936 0.161809 0.000000 Uiso 0.007123 Si
Si26 1.0 0.490194 0.344778 0.000000 Uiso 0.007123 Si
Al31 1.0 0.048714 0.795047 0.000000 Uiso 0.006733 Al
Al32 1.0 0.101286 0.204953 0.000000 Uiso 0.006733 Al
Al33 1.0 0.198714 0.704953 0.000000 Uiso 0.006733 Al
Al34 1.0 0.251286 0.295047 0.000000 Uiso 0.006733 Al
O111 1.0 0.010083 0.428592 0.000000 Uiso 0.008203 O
O112 1.0 0.038006 0.596214 0.000000 Uiso 0.008203 O
O113 1.0 0.488339 0.915842 0.000000 Uiso 0.008203 O
O114 1.0 0.459750 0.059352 0.000000 Uiso 0.008203 O
O121 1.0 0.060678 0.066846 0.000000 Uiso 0.008203 O
O122 1.0 0.089657 0.937509 0.000000 Uiso 0.008203 O
O123 1.0 0.438934 0.588720 0.000000 Uiso 0.008203 O
O124 1.0 0.411402 0.406925 0.000000 Uiso 0.008203 O
O131 1.0 0.111889 0.402985 0.000000 Uiso 0.008203 O
O132 1.0 0.139627 0.577329 0.000000 Uiso 0.008203 O
O133 1.0 0.390145 0.941449 0.000000 Uiso 0.008203 O
O134 1.0 0.361371 0.078237 0.000000 Uiso 0.008203 O
O141 1.0 0.159870 0.066112 0.000000 Uiso 0.008203 O
O142 1.0 0.188011 0.906391 0.000000 Uiso 0.008203 O
O143 1.0 0.338126 0.589454 0.000000 Uiso 0.008203 O
O144 1.0 0.309756 0.438043 0.000000 Uiso 0.008203 O
O151 1.0 0.211033 0.427728 0.000000 Uiso 0.008203 O
O152 1.0 0.239941 0.559633 0.000000 Uiso 0.008203 O
O153 1.0 0.289288 0.916706 0.000000 Uiso 0.008203 O
O154 1.0 0.261685 0.095933 0.000000 Uiso 0.008203 O
O211 1.0 0.012249 0.717963 0.260814 Uiso 0.013163 O
O212 1.0 0.037751 0.282037 0.236036 Uiso 0.013163 O
O221 1.0 0.062249 0.782037 0.251251 Uiso 0.013163 O
O222 1.0 0.087751 0.217963 0.255602 Uiso 0.013163 O
O231 1.0 0.112249 0.717963 0.237715 Uiso 0.013163 O
O232 1.0 0.137751 0.282037 0.257379 Uiso 0.013163 O
O241 1.0 0.162249 0.782037 0.263191 Uiso 0.013163 O
O242 1.0 0.187751 0.217963 0.235723 Uiso 0.013163 O
O251 1.0 0.212249 0.717963 0.246778 Uiso 0.013163 O
O252 1.0 0.237751 0.282037 0.259404 Uiso 0.013163 O
O31 1.0 0.325000 0.000000 0.000000 Uiso 0.019453 O
O32 1.0 0.375000 0.500000 0.000000 Uiso 0.019453 O
O33 1.0 0.425000 0.000000 0.000000 Uiso 0.019453 O
O34 1.0 0.475000 0.500000 0.000000 Uiso 0.019453 O
O41 1.0 0.029857 0.950792 0.000000 Uiso 0.011233 O
O42 1.0 0.120143 0.049208 0.000000 Uiso 0.011233 O
O43 1.0 0.179857 0.549208 0.000000 Uiso 0.011233 O
O44 1.0 0.270143 0.450792 0.000000 Uiso 0.011233 O

ADP components: [ Help ]

Atom site label U11 U22 U33 U12 U13 U23
Al11 0.00845 0.00652 0.00442 -0.00030 0.00000 0.00000
Al12 0.00845 0.00652 0.00442 0.00030 0.00000 0.00000
Al13 0.00845 0.00652 0.00442 -0.00030 0.00000 0.00000
Al14 0.00845 0.00652 0.00442 0.00030 0.00000 0.00000
Al15 0.00845 0.00652 0.00442 -0.00030 0.00000 0.00000
Al21 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Al22 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Al23 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Al24 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Al25 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Al26 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Al27 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Al28 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Al29 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Al210 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Si21 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Si22 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Si23 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Si24 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Si25 0.00641 0.00706 0.00790 0.00139 0.00000 0.00000
Si26 0.00641 0.00706 0.00790 -0.00139 0.00000 0.00000
Al31 0.00582 0.00778 0.00660 0.00097 0.00000 0.00000
Al32 0.00582 0.00778 0.00660 0.00097 0.00000 0.00000
Al33 0.00582 0.00778 0.00660 -0.00097 0.00000 0.00000
Al34 0.00582 0.00778 0.00660 -0.00097 0.00000 0.00000
O111 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O112 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O113 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O114 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O121 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O122 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O123 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O124 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O131 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O132 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O133 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O134 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O141 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O142 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O143 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O144 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O151 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O152 0.01136 0.00730 0.00595 -0.00112 0.00000 0.00000
O153 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O154 0.01136 0.00730 0.00595 0.00112 0.00000 0.00000
O211 0.01631 0.01407 0.00911 0.00693 0.00000 0.00000
O212 0.01631 0.01407 0.00911 0.00693 0.00000 0.00000
O221 0.01631 0.01407 0.00911 -0.00693 0.00000 0.00000
O222 0.01631 0.01407 0.00911 -0.00693 0.00000 0.00000
O231 0.01631 0.01407 0.00911 0.00693 0.00000 0.00000
O232 0.01631 0.01407 0.00911 0.00693 0.00000 0.00000
O241 0.01631 0.01407 0.00911 -0.00693 0.00000 0.00000
O242 0.01631 0.01407 0.00911 -0.00693 0.00000 0.00000
O251 0.01631 0.01407 0.00911 0.00693 0.00000 0.00000
O252 0.01631 0.01407 0.00911 0.00693 0.00000 0.00000
O31 0.01835 0.01503 0.02498 -0.00171 0.00000 0.00000
O32 0.01835 0.01503 0.02498 0.00171 0.00000 0.00000
O33 0.01835 0.01503 0.02498 -0.00171 0.00000 0.00000
O34 0.01835 0.01503 0.02498 0.00171 0.00000 0.00000
O41 0.01165 0.00752 0.01453 0.00144 0.00000 0.00000
O42 0.01165 0.00752 0.01453 0.00144 0.00000 0.00000
O43 0.01165 0.00752 0.01453 -0.00144 0.00000 0.00000
O44 0.01165 0.00752 0.01453 -0.00144 0.00000 0.00000