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Single-crystal X-ray diffraction of Cs3ScSi6O15 shows the presence of main reflections and satellite reflections up to the fourth order along the c* direction. The (3+1)-dimensional incommensurately modulated structure was solved in superspace group 
[a = 13.861 (1), c = 6.992 (1) Å, V = 1163.4 (2) Å3] with a modulation wavevector q = 0.14153 (2)c*. Refinement of three modulation waves for positional and anisotropic displacement parameter values for all atoms converged to Robs values for all, main and satellite reflections of first, second and third order of 0.0200, 0.0166, 0.0181, 0.0214 and 0.0303, respectively. Cs3ScSi6O15 forms a mixed tetrahedral-octahedral framework with prominent six-membered rings of [SiO4]-tetrahedra interconnected by [ScO6]-octahedra. Apart from Sc, all atoms are strongly affected by positional modulation with maximum atomic displacements of up to 0.93 Å causing rigid polyhedral arrangements to perform tilt and twist movements relative to each other, such as a rotation of the Sc-octahedra around the 
-axis by over 38°. Cs has an irregular coordination environment; however, considering distances up to 3.5 Å, the bond-valence sum changes by no more than 0.02 as a function of t and thus overall kept at a level of ca 1.075.
[a = 13.861 (1), c = 6.992 (1) Å, V = 1163.4 (2) Å3] with a modulation wavevector q = 0.14153 (2)c*. Refinement of three modulation waves for positional and anisotropic displacement parameter values for all atoms converged to Robs values for all, main and satellite reflections of first, second and third order of 0.0200, 0.0166, 0.0181, 0.0214 and 0.0303, respectively. Cs3ScSi6O15 forms a mixed tetrahedral-octahedral framework with prominent six-membered rings of [SiO4]-tetrahedra interconnected by [ScO6]-octahedra. Apart from Sc, all atoms are strongly affected by positional modulation with maximum atomic displacements of up to 0.93 Å causing rigid polyhedral arrangements to perform tilt and twist movements relative to each other, such as a rotation of the Sc-octahedra around the 
-axis by over 38°. Cs has an irregular coordination environment; however, considering distances up to 3.5 Å, the bond-valence sum changes by no more than 0.02 as a function of t and thus overall kept at a level of ca 1.075.Keywords: incommensurately modulated crystal structure; (3+1)-dimensional refinement; fourth-order satellite reflections; mixed tetrahedral-octahedral framework.
Supporting information
 | Crystallographic Information File (CIF) https://doi.org/10.1107/S2052520615022076/dk5038sup1.cif |
 | Portable Document Format (PDF) file https://doi.org/10.1107/S2052520615022076/dk5038sup2.pdf |
B-IncStrDB reference: 11472EwF4su
CCDC reference: 1437877
Computing details top
Data collection: CrysAlis PRO, Agilent Technologies, Version 1.171.37.34 (release 22-05-2014 CrysAlis171 .NET) (compiled May 22 2014,16:03:01); cell refinement: CrysAlis PRO, Agilent Technologies, Version 1.171.37.34 (release 22-05-2014 CrysAlis171 .NET) (compiled May 22 2014,16:03:01); data reduction: CrysAlis PRO, Agilent Technologies, Version 1.171.37.34 (release 22-05-2014 CrysAlis171 .NET) (compiled May 22 2014,16:03:01).
![[Figure 1]](http://journals.iucr.org/b/issues/2016/01/00/dk5038/dk5038fig1thm.gif)
![[Figure 2]](http://journals.iucr.org/b/issues/2016/01/00/dk5038/dk5038fig2thm.gif)
![[Figure 3]](http://journals.iucr.org/b/issues/2016/01/00/dk5038/dk5038fig3thm.gif)
![[Figure 4]](http://journals.iucr.org/b/issues/2016/01/00/dk5038/dk5038fig4thm.gif)
![[Figure 5]](http://journals.iucr.org/b/issues/2016/01/00/dk5038/dk5038fig5thm.gif)
![[Figure 6]](http://journals.iucr.org/b/issues/2016/01/00/dk5038/dk5038fig6thm.gif)
(I) top
Crystal data top
| Cs3O15ScSi6 | F(000) = 1170 |
| Mr = 852.2 | Dx = 3.649 Mg m−3 |
| Trigonal, X3m1(00γ)0s0† | Mo Kα radiation, λ = 0.71073 Å |
| q = 0.141530c* | Cell parameters from 7064 reflections |
| a = 13.8611 (13) Å | θ = 3.4–28.4° |
| c = 6.9924 (10) Å | µ = 7.95 mm−1 |
| V = 1163.4 (2) Å3 | T = 293 K |
| Z = 3 | 0.13 × 0.09 × 0.05 mm |
| † Symmetry operations: (1) x1, x2, x3, x4; (2) −x2, x1−x2, x3, x4; (3) −x2, −x1, x3, x4+1/2; (4) −x1, −x2, −x3, −x4; (5) −x1+x2, −x1, x3, x4; (6) x1, x1−x2, x3, x4+1/2; (7) x2, −x1+x2, −x3, −x4; (8) −x1+x2, x2, x3, x4+1/2; (9) x1−x2, x1, −x3, −x4; (10) x2, x1, −x3, −x4+1/2; (11) −x1, −x1+x2, −x3, −x4+1/2; (12) x1−x2, −x2, −x3, −x4+1/2; (13) x1+1/3, x2+2/3, x3+2/3, x4+1/3; (14) −x2+1/3, x1−x2+2/3, x3+2/3, x4+1/3; (15) −x2+1/3, −x1+2/3, x3+2/3, x4+5/6; (16) −x1+1/3, −x2+2/3, −x3+2/3, −x4+1/3; (17) −x1+x2+1/3, −x1+2/3, x3+2/3, x4+1/3; (18) x1+1/3, x1−x2+2/3, x3+2/3, x4+5/6; (19) x2+1/3, −x1+x2+2/3, −x3+2/3, −x4+1/3; (20) −x1+x2+1/3, x2+2/3, x3+2/3, x4+5/6; (21) x1−x2+1/3, x1+2/3, −x3+2/3, −x4+1/3; (22) x2+1/3, x1+2/3, −x3+2/3, −x4+5/6; (23) −x1+1/3, −x1+x2+2/3, −x3+2/3, −x4+5/6; (24) x1−x2+1/3, −x2+2/3, −x3+2/3, −x4+5/6; (25) x1+2/3, x2+1/3, x3+1/3, x4+2/3; (26) −x2+2/3, x1−x2+1/3, x3+1/3, x4+2/3; (27) −x2+2/3, −x1+1/3, x3+1/3, x4+1/6; (28) −x1+2/3, −x2+1/3, −x3+1/3, −x4+2/3; (29) −x1+x2+2/3, −x1+1/3, x3+1/3, x4+2/3; (30) x1+2/3, x1−x2+1/3, x3+1/3, x4+1/6; (31) x2+2/3, −x1+x2+1/3, −x3+1/3, −x4+2/3; (32) −x1+x2+2/3, x2+1/3, x3+1/3, x4+1/6; (33) x1−x2+2/3, x1+1/3, −x3+1/3, −x4+2/3; (34) x2+2/3, x1+1/3, −x3+1/3, −x4+1/6; (35) −x1+2/3, −x1+x2+1/3, −x3+1/3, −x4+1/6; (36) x1−x2+2/3, −x2+1/3, −x3+1/3, −x4+1/6. |
Data collection top
| Xcalibur, Ruby, Gemini ultra diffractometer | 2193 independent reflections |
| Radiation source: X-ray tube | 1838 reflections with I > 3σ(I) |
| Graphite monochromator | Rint = 0.032 |
| Detector resolution: 10.3575 pixels mm-1 | θmax = 28.7°, θmin = 3.2° |
| ω scans | h = −18→17 |
| Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.37.34 (release 22-05-2014 CrysAlis171 .NET) (compiled May 22 2014,16:03:01) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. | k = −18→18 |
| Tmin = 0.558, Tmax = 0.733 | l = −9→9 |
| 17243 measured reflections |
Refinement top
| Refinement on F | 0 restraints |
| R[F2 > 2σ(F2)] = 0.020 | 0 constraints |
| wR(F2) = 0.026 | Weighting scheme based on measured s.u.'s w = 1/(σ2(F) + 0.0001F2) |
| S = 1.16 | (Δ/σ)max = 0.042 |
| 2193 reflections | Δρmax = 0.38 e Å−3 |
| 130 parameters | Δρmin = −0.35 e Å−3 |
Crystal data top
| Cs3O15ScSi6 | V = 1163.4 (2) Å3 |
| Mr = 852.2 | Z = 3 |
| Trigonal, X3m1(00γ)0s0† | Mo Kα radiation |
| q = 0.141530c* | µ = 7.95 mm−1 |
| a = 13.8611 (13) Å | T = 293 K |
| c = 6.9924 (10) Å | 0.13 × 0.09 × 0.05 mm |
| † Symmetry operations: (1) x1, x2, x3, x4; (2) −x2, x1−x2, x3, x4; (3) −x2, −x1, x3, x4+1/2; (4) −x1, −x2, −x3, −x4; (5) −x1+x2, −x1, x3, x4; (6) x1, x1−x2, x3, x4+1/2; (7) x2, −x1+x2, −x3, −x4; (8) −x1+x2, x2, x3, x4+1/2; (9) x1−x2, x1, −x3, −x4; (10) x2, x1, −x3, −x4+1/2; (11) −x1, −x1+x2, −x3, −x4+1/2; (12) x1−x2, −x2, −x3, −x4+1/2; (13) x1+1/3, x2+2/3, x3+2/3, x4+1/3; (14) −x2+1/3, x1−x2+2/3, x3+2/3, x4+1/3; (15) −x2+1/3, −x1+2/3, x3+2/3, x4+5/6; (16) −x1+1/3, −x2+2/3, −x3+2/3, −x4+1/3; (17) −x1+x2+1/3, −x1+2/3, x3+2/3, x4+1/3; (18) x1+1/3, x1−x2+2/3, x3+2/3, x4+5/6; (19) x2+1/3, −x1+x2+2/3, −x3+2/3, −x4+1/3; (20) −x1+x2+1/3, x2+2/3, x3+2/3, x4+5/6; (21) x1−x2+1/3, x1+2/3, −x3+2/3, −x4+1/3; (22) x2+1/3, x1+2/3, −x3+2/3, −x4+5/6; (23) −x1+1/3, −x1+x2+2/3, −x3+2/3, −x4+5/6; (24) x1−x2+1/3, −x2+2/3, −x3+2/3, −x4+5/6; (25) x1+2/3, x2+1/3, x3+1/3, x4+2/3; (26) −x2+2/3, x1−x2+1/3, x3+1/3, x4+2/3; (27) −x2+2/3, −x1+1/3, x3+1/3, x4+1/6; (28) −x1+2/3, −x2+1/3, −x3+1/3, −x4+2/3; (29) −x1+x2+2/3, −x1+1/3, x3+1/3, x4+2/3; (30) x1+2/3, x1−x2+1/3, x3+1/3, x4+1/6; (31) x2+2/3, −x1+x2+1/3, −x3+1/3, −x4+2/3; (32) −x1+x2+2/3, x2+1/3, x3+1/3, x4+1/6; (33) x1−x2+2/3, x1+1/3, −x3+1/3, −x4+2/3; (34) x2+2/3, x1+1/3, −x3+1/3, −x4+1/6; (35) −x1+2/3, −x1+x2+1/3, −x3+1/3, −x4+1/6; (36) x1−x2+2/3, −x2+1/3, −x3+1/3, −x4+1/6. |
Data collection top
| Xcalibur, Ruby, Gemini ultra diffractometer | 2193 independent reflections |
| Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.37.34 (release 22-05-2014 CrysAlis171 .NET) (compiled May 22 2014,16:03:01) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. | 1838 reflections with I > 3σ(I) |
| Tmin = 0.558, Tmax = 0.733 | Rint = 0.032 |
| 17243 measured reflections |
Refinement top
| R[F2 > 2σ(F2)] = 0.020 | 130 parameters |
| wR(F2) = 0.026 | 0 restraints |
| S = 1.16 | Δρmax = 0.38 e Å−3 |
| 2193 reflections | Δρmin = −0.35 e Å−3 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
| x | y | z | Uiso*/Ueq | ||
| Cs1 | 0.5 | 0 | 0.5 | 0.02358 (8) | |
| Sc1 | 0 | 0 | 0 | 0.00520 (19) | |
| Si1 | 0.102025 (18) | 0.20405 (4) | 0.36553 (6) | 0.00563 (15) | |
| O1 | 0.18212 (8) | 0.18212 (8) | 0.5 | 0.0129 (4) | |
| O2 | 0.166666 | 0.333333 | 0.333333 | 0.0133 (7) | |
| O3 | 0.07041 (5) | 0.14082 (10) | 0.17032 (17) | 0.0139 (4) |
Atomic displacement parameters (Å2) top
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Cs1 | 0.03067 (13) | 0.02203 (11) | 0.01517 (11) | 0.01102 (5) | −0.00410 (3) | −0.00820 (7) |
| Sc1 | 0.0060 (2) | 0.0060 (2) | 0.0036 (3) | 0.00300 (11) | 0 | 0 |
| Si1 | 0.00639 (16) | 0.0050 (2) | 0.0050 (2) | 0.00252 (11) | 0.00015 (8) | 0.00030 (17) |
| O1 | 0.0143 (4) | 0.0143 (4) | 0.0124 (6) | 0.0089 (5) | −0.0021 (2) | 0.0021 (2) |
| O2 | 0.0130 (10) | 0.0061 (8) | 0.0183 (10) | 0.0031 (4) | 0.0007 (3) | 0.0015 (7) |
| O3 | 0.0172 (5) | 0.0127 (6) | 0.0101 (6) | 0.0064 (3) | −0.0022 (2) | −0.0043 (5) |
Bond lengths (Å) top
| Average | Minimum | Maximum | |
| Cs1—O1i | 3.274 (4) | 3.187 (5) | 3.405 (5) |
| Cs1—O1ii | 3.274 (4) | 3.187 (5) | 3.405 (5) |
| Cs1—O1iii | 3.275 (4) | 3.187 (5) | 3.406 (5) |
| Cs1—O1iv | 3.276 (4) | 3.187 (5) | 3.406 (5) |
| Cs1—O3v | 3.505 (6) | 3.204 (6) | 3.829 (6) |
| Cs1—O3iii | 3.511 (4) | 3.204 (4) | 3.830 (4) |
| Cs1—O3vi | 3.507 (6) | 3.204 (6) | 3.829 (6) |
| Cs1—O3vii | 3.508 (4) | 3.204 (4) | 3.830 (4) |
| Sc1—O3 | 2.111 (2) | 2.100 (2) | 2.122 (2) |
| Sc1—O3viii | 2.111 (2) | 2.100 (3) | 2.122 (3) |
| Sc1—O3ix | 2.111 (2) | 2.100 (2) | 2.122 (2) |
| Sc1—O3x | 2.111 (5) | 2.100 (6) | 2.121 (6) |
| Sc1—O3xi | 2.111 (2) | 2.100 (3) | 2.122 (3) |
| Sc1—O3xii | 2.111 (5) | 2.100 (6) | 2.121 (6) |
| Si1—O1 | 1.633 (5) | 1.614 (5) | 1.653 (5) |
| Si1—O1xiii | 1.633 (5) | 1.614 (7) | 1.653 (7) |
| Si1—O2 | 1.628 (2) | 1.611 (3) | 1.639 (3) |
| Si1—O3 | 1.569 (2) | 1.567 (2) | 1.571 (2) |
| Symmetry codes: (i) x1+1/3, x2−1/3, x3−1/3, x4+1/3; (ii) −x2+2/3, −x1+1/3, x3+1/3, x4+1/6; (iii) −x1+x2+2/3, −x1+1/3, x3+1/3, x4+2/3; (iv) −x1+x2+1/3, x2−1/3, x3−1/3, x4+5/6; (v) −x2+2/3, x1−x2+1/3, x3+1/3, x4+2/3; (vi) x2+1/3, −x1+x2−1/3, −x3+2/3, −x4+1/3; (vii) x1−x2+1/3, x1−1/3, −x3+2/3, −x4+1/3; (viii) −x2, x1−x2, x3, x4; (ix) −x1, −x2, −x3, −x4; (x) −x1+x2, −x1, x3, x4; (xi) x2, −x1+x2, −x3, −x4; (xii) x1−x2, x1, −x3, −x4; (xiii) −x1+x2, x2, x3, x4+1/2. |
Experimental details
| Crystal data | |
| Chemical formula | Cs3O15ScSi6 |
| Mr | 852.2 |
| Crystal system, space group | Trigonal, X3m1(00γ)0s0† |
| Temperature (K) | 293 |
| Wave vectors | q = 0.141530c* |
| a, c (Å) | 13.8611 (13), 6.9924 (10) |
| V (Å3) | 1163.4 (2) |
| Z | 3 |
| Radiation type | Mo Kα |
| µ (mm−1) | 7.95 |
| Crystal size (mm) | 0.13 × 0.09 × 0.05 |
| Data collection | |
| Diffractometer | Xcalibur, Ruby, Gemini ultra |
| Absorption correction | Analytical CrysAlis PRO, Agilent Technologies, Version 1.171.37.34 (release 22-05-2014 CrysAlis171 .NET) (compiled May 22 2014,16:03:01) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. |
| Tmin, Tmax | 0.558, 0.733 |
| No. of measured, independent and observed [I > 3σ(I)] reflections | 17243, 2193, 1838 |
| Rint | 0.032 |
| (sin θ/λ)max (Å−1) | 0.675 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.020, 0.026, 1.16 |
| No. of reflections | 2193 |
| No. of parameters | 130 |
| Δρmax, Δρmin (e Å−3) | 0.38, −0.35 |
† Symmetry operations: (1) x1, x2, x3, x4; (2) −x2, x1−x2, x3, x4; (3) −x2, −x1, x3, x4+1/2; (4) −x1, −x2, −x3, −x4; (5) −x1+x2, −x1, x3, x4; (6) x1, x1−x2, x3, x4+1/2; (7) x2, −x1+x2, −x3, −x4; (8) −x1+x2, x2, x3, x4+1/2; (9) x1−x2, x1, −x3, −x4; (10) x2, x1, −x3, −x4+1/2; (11) −x1, −x1+x2, −x3, −x4+1/2; (12) x1−x2, −x2, −x3, −x4+1/2; (13) x1+1/3, x2+2/3, x3+2/3, x4+1/3; (14) −x2+1/3, x1−x2+2/3, x3+2/3, x4+1/3; (15) −x2+1/3, −x1+2/3, x3+2/3, x4+5/6; (16) −x1+1/3, −x2+2/3, −x3+2/3, −x4+1/3; (17) −x1+x2+1/3, −x1+2/3, x3+2/3, x4+1/3; (18) x1+1/3, x1−x2+2/3, x3+2/3, x4+5/6; (19) x2+1/3, −x1+x2+2/3, −x3+2/3, −x4+1/3; (20) −x1+x2+1/3, x2+2/3, x3+2/3, x4+5/6; (21) x1−x2+1/3, x1+2/3, −x3+2/3, −x4+1/3; (22) x2+1/3, x1+2/3, −x3+2/3, −x4+5/6; (23) −x1+1/3, −x1+x2+2/3, −x3+2/3, −x4+5/6; (24) x1−x2+1/3, −x2+2/3, −x3+2/3, −x4+5/6; (25) x1+2/3, x2+1/3, x3+1/3, x4+2/3; (26) −x2+2/3, x1−x2+1/3, x3+1/3, x4+2/3; (27) −x2+2/3, −x1+1/3, x3+1/3, x4+1/6; (28) −x1+2/3, −x2+1/3, −x3+1/3, −x4+2/3; (29) −x1+x2+2/3, −x1+1/3, x3+1/3, x4+2/3; (30) x1+2/3, x1−x2+1/3, x3+1/3, x4+1/6; (31) x2+2/3, −x1+x2+1/3, −x3+1/3, −x4+2/3; (32) −x1+x2+2/3, x2+1/3, x3+1/3, x4+1/6; (33) x1−x2+2/3, x1+1/3, −x3+1/3, −x4+2/3; (34) x2+2/3, x1+1/3, −x3+1/3, −x4+1/6; (35) −x1+2/3, −x1+x2+1/3, −x3+1/3, −x4+1/6; (36) x1−x2+2/3, −x2+1/3, −x3+1/3, −x4+1/6.
Computer programs: CrysAlis PRO, Agilent Technologies, Version 1.171.37.34 (release 22-05-2014 CrysAlis171 .NET) (compiled May 22 2014, 16:03:01).
