The modulated low-temperature structure of malayaite, CaSnOSiO4

Authors:

Malcherek, Thomas; Paulenz, Bianca; Fischer, Michael; Paulmann, Carsten

Journal:

Acta Crystallographica Section B 76 316-321 (2020)

DOI:

https://doi.org/10.1107/S2052520620003807

B-IncStrDB ID: 16372EQKyWN Entry date: 2020-04-03 Last revision: 2021-12-12

I

Chemical data


Structural Formula Sum: Ca1 O5 Si1 Sn1 [ Help ]

Formula weight: 266.9 Da [ Help ]

Crystallographic data and experimental details


Crystal system: monoclinic [ Help ]

Superspace group name: C2/c(0β0)s0 [ Help ]

Symmetry operations of the superspace group: [ Help ]

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

a: 6.6663(3) Å [ Help ]

b: 8.8954(4) Å [ Help ]

c: 7.1475(3) Å [ Help ]

α: 90 ° [ Help ]

β: 113.405(5) ° [ Help ]

γ: 90 ° [ Help ]

Volume: 388.97(3) Å3 [ Help ]

Modulation dimension: 1 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0.000000 0.260600 0.000000

Z: 4 [ Help ]

Cell determination reflection Nb.: 7943 [ Help ]

θ(min) for cell determination: 2.69 ° [ Help ]

θ(max) for cell determination: 51.02 ° [ Help ]

Cell measurement temperature: 20 K [ Help ]

μ: 5.527 mm-1 [ Help ]

Absorption correction type: multi-scan [ Help ]

Absorption correction remarks: CrysAlisPro 1.171.38.46 (Rigaku Oxford Diffraction, 2015) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. [ Help ]

Minimum transmission factor: 0.742 [ Help ]

Maximum transmission factor: 1 [ Help ]

Refinement details


Total nb. of reflections: 7250 [ Help ]

Nb. of observed reflections: 5161 [ Help ]

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

Refinement based on: Fsqd [ Help ]

R(obs): 0.0436 [ Help ]

wR(obs): 0.1862 [ Help ]

R(all): 0.0490 [ Help ]

wR(all): 0.2040 [ Help ]

S(all): 1.30 [ Help ]

S(obs): 1.40 [ Help ]

Nb. of reflections: 7250 [ Help ]

Nb. of parameters: 68 [ Help ]

Weighting scheme: sigma [ Help ]

Weighting scheme remarks: w=1/(σ2(I)+0.01I2) [ Help ]

Δ/σ(max): 0.0007 [ Help ]

Δ/σ(mean): 0.0001 [ Help ]

Δρ(max): 1.48 e_Å-3 [ Help ]

Δρ(min): -2.04 e_Å-3 [ Help ]

Extinction method: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974) [ Help ]

Extinction coefficient: 9000(1200) [ 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 Disordered cluster Disordered group
Sn Sn 0 0 0 Uani 0.00218(5) 4 1 d ? ? ?
Si Si 0 0.68161(8) 0.25 Uani 0.00251(8) 4 1 d ? ? ?
Ca Ca 0 0.33686(4) 0.25 Uani 0.00636(6) 4 1 d ? ? ?
O1 O 0 0.08680(8) 0.25 Uani 0.00419(13) 4 1 d ? ? ?
O2 O 0.32451(8) 0.06735(6) 0.08692(6) Uani 0.00470(10) 8 1 d ? ? ?
O3 O 0.39036(8) 0.28755(6) 0.37253(6) Uani 0.00441(10) 8 1 d ? ? ?

ADP components: [ Help ]

Atom site label Atom site symbol U11 U22 U33 U12 U13 U23
Sn Sn 0.00195(7) 0.00243(7) 0.00197(6) -0.000036(7) 0.00059(4) -0.000037(7)
Si Si 0.00203(12) 0.00273(16) 0.00246(9) 0 0.00057(7) 0
Ca Ca 0.00311(9) 0.00301(9) 0.01036(8) 0 -0.00008(6) 0
O1 O 0.0063(2) 0.0032(2) 0.00339(13) 0 0.00219(12) 0
O2 O 0.00358(15) 0.00427(16) 0.00513(11) -0.00070(10) 0.00053(9) -0.00116(9)
O3 O 0.00412(15) 0.00376(18) 0.00522(12) -0.00012(9) 0.00172(9) -0.00076(9)

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

Wave vector code q_1
1 1

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

Modulation code Atom site label Displacement axis Wave vector code
Snx1 Sn x 1
Sny1 Sn y 1
Snz1 Sn z 1
Six1 Si x 1
Siy1 Si y 1
Siz1 Si z 1
Cax1 Ca x 1
Cay1 Ca y 1
Caz1 Ca 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
O3x1 O3 x 1
O3y1 O3 y 1
O3z1 O3 z 1

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Snx1 0 -0.001232(7)
Sny1 0 0.000334(3)
Snz1 0 0.001413(7)
Six1 0.00050(3) -0.00142(3)
Siy1 0 0
Siz1 0.00014(2) 0.00129(2)
Cax1 0.001127(18) -0.001361(19)
Cay1 0 0
Caz1 -0.00415(2) 0.00326(2)
O1x1 0.00092(6) -0.00137(6)
O1y1 0 0
O1z1 -0.00011(5) 0.00137(5)
O2x1 -0.00006(4) -0.00127(4)
O2y1 0.00099(3) -0.00005(3)
O2z1 -0.00161(4) 0.00124(4)
O3x1 0.00102(4) -0.00152(4)
O3y1 -0.00026(3) -0.00016(3)
O3z1 0.00038(4) 0.00141(4)

II

Chemical data


Structural Formula Sum: Ca1 O5 Si1 Sn1 [ Help ]

Formula weight: 266.9 Da [ Help ]

Crystallographic data and experimental details


Crystal system: monoclinic [ Help ]

Space group name (H-M): C 1 2/c 1 [ Help ]

Space group name (Hall): -C 2yc [ Help ]

Space group nb.: 15 [ Help ]

Symmetry operations of the space group: [ Help ]

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

a: 6.6667(2) Å [ Help ]

b: 8.8934(3) Å [ Help ]

c: 7.1520(3) Å [ Help ]

α: 90 ° [ Help ]

β: 113.323(3) ° [ Help ]

γ: 90 ° [ Help ]

Volume: 389.39(3) Å3 [ Help ]

Z: 4 [ Help ]

Cell determination reflection Nb.: 11467 [ Help ]

θ(min) for cell determination: 3.67 ° [ Help ]

θ(max) for cell determination: 51 ° [ Help ]

Cell measurement temperature: 298 K [ Help ]

μ: 5.521 mm-1 [ Help ]

Absorption correction type: multi-scan [ Help ]

Absorption correction remarks: CrysAlisPro 1.171.38.46 (Rigaku Oxford Diffraction, 2015) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. [ Help ]

Minimum transmission factor: 0.754 [ Help ]

Maximum transmission factor: 1 [ Help ]

Refinement details


Total nb. of reflections: 2748 [ Help ]

Nb. of observed reflections: 2651 [ Help ]

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

Refinement based on: Fsqd [ Help ]

R(obs): 0.0258 [ Help ]

wR(obs): 0.1104 [ Help ]

R(all): 0.0263 [ Help ]

wR(all): 0.1127 [ Help ]

S(all): 1.06 [ Help ]

S(obs): 1.05 [ Help ]

Nb. of reflections: 2748 [ Help ]

Nb. of parameters: 41 [ Help ]

Weighting scheme: sigma [ Help ]

Weighting scheme remarks: w=1/(σ2(I)+0.01I2) [ Help ]

Δ/σ(max): 0.0007 [ Help ]

Δ/σ(mean): 0.0001 [ Help ]

Δρ(max): 0.70 e_Å-3 [ Help ]

Δρ(min): -0.67 e_Å-3 [ Help ]

Extinction method: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974) [ Help ]

Extinction coefficient: 5800(900) [ 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 Disordered cluster Disordered group
Sn Sn 0 0 0 Uani 0.00385(4) 4 1 d ? ? ?
Si Si 0 0.68145(5) 0.25 Uani 0.00444(6) 4 1 d ? ? ?
Ca Ca 0 0.33729(4) 0.25 Uani 0.01704(7) 4 1 d ? ? ?
O1 O 0 0.08665(6) 0.25 Uani 0.00729(10) 4 1 d ? ? ?
O2 O 0.32452(6) 0.06780(5) 0.08695(6) Uani 0.00756(7) 8 1 d ? ? ?
O3 O 0.39029(6) 0.28799(4) 0.37214(5) Uani 0.00670(8) 8 1 d ? ? ?

ADP components: [ Help ]

Atom site label Atom site symbol U11 U22 U33 U12 U13 U23
Sn Sn 0.00400(5) 0.00386(5) 0.00362(5) -0.000007(5) 0.00145(4) -0.000202(5)
Si Si 0.00380(8) 0.00502(13) 0.00446(8) 0 0.00157(6) 0
Ca Ca 0.00667(7) 0.00372(8) 0.03245(15) 0 -0.00108(7) 0
O1 O 0.01245(16) 0.00528(15) 0.00510(12) 0 0.00450(11) 0
O2 O 0.00522(10) 0.00704(11) 0.00912(11) -0.00141(7) 0.00147(7) -0.00274(8)
O3 O 0.00687(10) 0.00537(13) 0.00879(11) -0.00077(7) 0.00408(8) -0.00228(7)