Incommensurate modulation and thermal expansion of Sr3B2+xSi1-xO8-x/2 solid solutions

Authors:

Volkov, Sergey; Bubnova, Rimma; Bolotina, Nadezhda; Krzhizhanovskaya, Maria; Belousova, Olga; Filatov, Stanislav

Journal:

Acta Crystallographica, Section B 71 489-497 (2015)

DOI:

https://doi.org/10.1107/S2052520615011713

B-IncStrDB ID: 11322EzrAh2 Entry date: 2015-10-02 Last revision: 2022-01-02

I

Chemical data


Structural Formula Sum: B3.041 O10.479 Si0.959 Sr4 [ Help ]

Formula weight: 577.9 Da [ Help ]

Crystallographic data and experimental details


Crystal system: orthorhombic [ Help ]

Space group name (H-M): P n m a [ Help ]

Space group name (Hall): -P -2xabc;-2yb;-2zac [ Help ]

Symmetry operations of the space group: [ Help ]

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

a: 12.2774 Å [ Help ]

b: 3.9006 Å [ Help ]

c: 5.4091 Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 259.038 Å3 [ Help ]

Z: 1 [ Help ]

Cell measurement temperature: 293 K [ Help ]

μ: 20.637 mm-1 [ Help ]

Refinement details


Total nb. of reflections: 1031 [ Help ]

Nb. of observed reflections: 428 [ Help ]

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

Refinement based on: F [ Help ]

R(all): 0.2015 [ Help ]

R(obs): 0.0765 [ Help ]

wR(obs): 0.0772 [ Help ]

wR(all): 0.0907 [ Help ]

S(all): 2.34 [ Help ]

Nb. of reflections: 1031 [ Help ]

Nb. of parameters: 29 [ Help ]

Number of constraints: 1 [ Help ]

Weighting scheme: sigma [ Help ]

Weighting scheme remarks: w=1/(σ2(F)+0.0001F2) [ Help ]

Δ/σ(max): 0.0012 [ Help ]

Δ/σ(mean): 0.0003 [ Help ]

Δρ(max): 3.58 e_Å-3 [ Help ]

Δρ(min): -5.05 e_Å-3 [ Help ]

Extinction method: none [ Help ]

Structural Information


Average Structure: [ 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
Sr Sr 0.14594(9) 0.75 0.90476(13) 0.0386(3) Uani d ? 1 ? ?
B B 0.4073(18) 0.82(4) 0.914(4) 0.0208(18) Uiso d ? 0.3802 ? ?
Si Si 0.4199(10) 0.75 0.944(2) 0.0208(18) Uiso d ? 0.2395 ? ?
O O1 0.4236(12) 0.75 0.681(2) 0.024(2) Uiso d ? 0.5 ? ?
O O2 0.51(3) 0.527(7) 0.919(3) 0.078(7) Uiso d ? 0.3097 ? ?
O O3 0.334(9) 0.75 0.1031(11) 0.056(3) Uani d ? 1 ? ?
O O4 0.3665(12) 0.75 0.675(2) 0.025(2) Uiso d ? 0.5 ? ?

ADP components: [ Help ]

Atom site label U11 U22 U33 U12 U13 U23 Atom site symbol
Sr 0.0765(8) 0.0153(3) 0.0241(4) 0 -0.0166(4) 0 Sr
O3 0.102(8) 0.026(3) 0.04(4) 0 0.024(4) 0 O

II

Chemical data


Structural Formula Sum: B3.376 O10.312 Si0.624 Sr4 [ Help ]

Formula weight: 569.5 Da [ Help ]

Crystallographic data and experimental details


Crystal system: orthorhombic [ Help ]

Space group name (H-M): P n m a [ Help ]

Symmetry operations of the superspace group: [ Help ]

Operation code Operation in algebraic form
1 x1,x2,x3,x4,x5
2 -x1+1/2,-x2,x3+1/2,x5,x4
3 -x1,x2+1/2,-x3,-x5,-x4
4 x1+1/2,-x2+1/2,-x3+1/2,-x4,-x5
5 -x1,-x2,-x3,-x4,-x5
6 x1+1/2,x2,-x3+1/2,-x5,-x4
7 x1,-x2+1/2,x3,x5,x4
8 -x1+1/2,x2+1/2,x3+1/2,x4,x5

a: 12.178(2) Å [ Help ]

b: 3.8801(8) Å [ Help ]

c: 5.387(11) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 254.55(9) Å3 [ Help ]

Z: 1 [ Help ]

Cell measurement temperature: 293 K [ Help ]

Modulation dimension: 2 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0 0.033 0.418
2 0 -0.033 0.418

μ: 20.959 mm-1 [ Help ]

Refinement details


Total nb. of reflections: 1403 [ Help ]

Nb. of observed reflections: 441 [ Help ]

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

Refinement based on: F [ Help ]

R(all): 0.1756 [ Help ]

R(obs): 0.0605 [ Help ]

wR(obs): 0.0607 [ Help ]

wR(all): 0.0677 [ Help ]

S(all): 2.35 [ Help ]

Nb. of reflections: 1403 [ Help ]

Nb. of parameters: 35 [ Help ]

Number of constraints: 4 [ Help ]

Weighting scheme: sigma [ Help ]

Weighting scheme remarks: w=1/(σ2(F)+0.0001F2) [ Help ]

Δ/σ(max): 0.0053 [ Help ]

Δ/σ(mean): 0.0011 [ Help ]

Δρ(max): 0.94 e_Å-3 [ Help ]

Δρ(min): -1.19 e_Å-3 [ Help ]

Extinction method: none [ Help ]

Structural Information


Average Structure: [ 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
Sr Sr 0.14481(6) 0.75 0.90534(10) 0.02953(19) Uani d ? 1 ? ?
B B 0.4089(10) 0.815(2) 0.916(2) 0.0202(15) Uiso d ? 0.422 ? ?
Si Si 0.4202(11) 0.75 0.949(2) 0.0202(15) Uiso d ? 0.156 ? ?
O O1 0.4301(7) 0.75 0.6826(15) 0.0221(11) Uiso d ? 0.5 ? ?
O O2 0.5088(11) 0.519(4) 0.917(2) 0.049(3) Uiso d ? 0.289 ? ?
O O3 0.3323(4) 0.75 0.1005(9) 0.0354(13) Uiso d ? 1 ? ?
O O4 0.3681(7) 0.75 0.6769(15) 0.0221(11) Uiso d ? 0.5 ? ?

ADP components: [ Help ]

Atom site label U11 U22 U33 U12 U13 U23 Atom site symbol
Sr 0.0546(4) 0.0136(2) 0.0204(3) 0 -0.0167(3) 0 Sr

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

Wave vector code q_1 q_2
1 1 0
2 0 1

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

Modulation code Atom site label Displacement axis Wave vector code
Srx1 Sr x 1
Sry1 Sr y 1
Srz1 Sr z 1
Srx2 Sr x 2
Sry2 Sr y 2
Srz2 Sr z 2
O3x1 O3 x 1
O3y1 O3 y 1
O3z1 O3 z 1
O3x2 O3 x 2
O3y2 O3 y 2
O3z2 O3 z 2

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Srx1 0.00399(15) 0.00361(15)
Sry1 0 0
Srz1 0(4) 0.0044(5)
Srx2 0.00399(15) 0.00361(15)
Sry2 0 0
Srz2 0(4) 0.0044(5)
O3x1 0.0048(10) 0.0076(10)
O3y1 0 0
O3z1 0 0
O3x2 0.0048(10) 0.0076(10)
O3y2 0 0
O3z2 0 0

Definition of the occupation Fourier series: [ Help ]

Modulation code Atom site label Wave vector code
O1o1 O1 1
O1o2 O1 2
O2o1 O2 1
O2o2 O2 2
O4o1 O4 1
O4o2 O4 2

Occupation Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
O1o1 -0.048(19) 0.04(2)
O1o2 -0.048(19) 0.04(2)
O2o1 0 0.18(4)
O2o2 0 0.18(4)
O4o1 0.048(19) -0.04(2)
O4o2 0.048(19) -0.04(2)

III

Chemical data


Structural Formula Sum: B3.704 O10.148 Si0.296 Sr4 [ Help ]

Formula weight: 561.2 Da [ Help ]

Crystallographic data and experimental details


Crystal system: orthorhombic [ Help ]

Space group name (H-M): P n m a [ Help ]

Symmetry operations of the superspace group: [ Help ]

Operation code Operation in algebraic form
1 x1,x2,x3,x4,x5
2 -x1+1/2,-x2,x3+1/2,x5,x4
3 -x1,x2+1/2,-x3,-x5,-x4
4 x1+1/2,-x2+1/2,-x3+1/2,-x4,-x5
5 -x1,-x2,-x3,-x4,-x5
6 x1+1/2,x2,-x3+1/2,-x5,-x4
7 x1,-x2+1/2,x3,x5,x4
8 -x1+1/2,x2+1/2,x3+1/2,x4,x5

a: 12.089 Å [ Help ]

b: 3.8635 Å [ Help ]

c: 5.378 Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 251.184 Å3 [ Help ]

Z: 1 [ Help ]

Cell measurement temperature: 293 K [ Help ]

Modulation dimension: 2 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0 0.041 0.378
2 0 -0.041 0.378

μ: 21.198 mm-1 [ Help ]

Refinement details


Total nb. of reflections: 1431 [ Help ]

Nb. of observed reflections: 431 [ Help ]

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

Refinement based on: F [ Help ]

R(all): 0.2089 [ Help ]

R(obs): 0.0806 [ Help ]

wR(obs): 0.0758 [ Help ]

wR(all): 0.083 [ Help ]

S(all): 2.64 [ Help ]

Nb. of reflections: 1431 [ Help ]

Nb. of parameters: 35 [ Help ]

Number of constraints: 4 [ Help ]

Weighting scheme: sigma [ Help ]

Weighting scheme remarks: w=1/(σ2(F)+0.0001F2) [ Help ]

Δ/σ(max): 0.0055 [ Help ]

Δ/σ(mean): 0.0007 [ Help ]

Δρ(max): 1.09 e_Å-3 [ Help ]

Δρ(min): -4.63 e_Å-3 [ Help ]

Extinction method: none [ Help ]

Structural Information


Average Structure: [ 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
Sr Sr 0.14443(7) 0.75 0.90653(14) 0.0238(3) Uani d ? 1 ? ?
B B 0.4082(12) 0.816(2) 0.924(3) 0.019(3) Uiso d ? 0.463 ? ?
Si Si 0.422(3) 0.75 0.952(8) 0.019(3) Uiso d ? 0.074 ? ?
O O1 0.4304(10) 0.75 0.692(2) 0.0244(15) Uiso d ? 0.5 ? ?
O O2 0.5067(15) 0.493(5) 0.908(3) 0.046(4) Uiso d ? 0.2685 ? ?
O O3 0.3336(6) 0.75 0.0995(13) 0.0335(17) Uiso d ? 1 ? ?
O O4 0.3669(10) 0.75 0.683(2) 0.0244(15) Uiso d ? 0.5 ? ?

ADP components: [ Help ]

Atom site label U11 U22 U33 U12 U13 U23 Atom site symbol
Sr 0.0433(7) 0.0125(3) 0.0157(5) 0 -0.0109(5) 0 Sr

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

Wave vector code q_1 q_2
1 1 0
2 0 1

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

Modulation code Atom site label Displacement axis Wave vector code
Srx1 Sr x 1
Sry1 Sr y 1
Srz1 Sr z 1
Srx2 Sr x 2
Sry2 Sr y 2
Srz2 Sr z 2
O3x1 O3 x 1
O3y1 O3 y 1
O3z1 O3 z 1
O3x2 O3 x 2
O3y2 O3 y 2
O3z2 O3 z 2

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Srx1 0.0052(2) 0.0058(2)
Sry1 0 0
Srz1 -0.0078(6) -0.0048(6)
Srx2 0.0052(2) 0.0058(2)
Sry2 0 0
Srz2 -0.0078(6) -0.0048(6)
O3x1 0.0042(17) 0.0086(14)
O3y1 0 0
O3z1 0 0
O3x2 0.0042(17) 0.0086(14)
O3y2 0 0
O3z2 0 0

Definition of the occupation Fourier series: [ Help ]

Modulation code Atom site label Wave vector code
O1o1 O1 1
O1o2 O1 2
O2o1 O2 1
O2o2 O2 2
O4o1 O4 1
O4o2 O4 2

Occupation Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
O1o1 -0.14(3) -0.31(4)
O1o2 -0.14(3) -0.31(4)
O2o1 0 0.33(7)
O2o2 0 0.32(7)
O4o1 0.14(3) 0.31(4)
O4o2 0.14(3) 0.31(4)