The modulated low-temperature structure of malayaite, CaSnOSiO₄

The crystal structure of the mineral malayaite has been studied by single-crystal X-ray diffraction at a temperature of 20 K and by calculation of its phonon dispersion using density functional perturbation theory. The X-ray diffraction data show first-order satellite diffraction maxima at positions q = 0.2606 (8)b*, that are absent at room temperature. The computed phonon dispersion indicates unstable modes associated with dynamic displacements of the Ca atoms. The largest-frequency modulus of these phonon instabilities is located close to a wavevector of q = 0.3b*. These results indicate that the malayaite crystal structure is incommensurately modulated by static displacement of the Ca atoms at low temperatures, caused by the softening of an optic phonon with B_g symmetry.

1. Introduction

Malayaite is the tin analogue of the common accessory mineral titanite, CaTiOSiO₄ (Takenouchi, 1976; Higgins & Ribbe, 1977). The crystal structure of malayaite at room temperature is described in space group C2/c.¹ It consists of parallel, kinked chains of corner-sharing SnO₆ octahedra, laterally connected by isolated SiO₄ tetrahedra. In contrast to malayaite, pure titanite transforms from C2/c to P2₁/c at temperatures below 490 K (Taylor & Brown, 1976), forming a crystal structure with ordered out-of-centre displacements of the Ti atoms inside their distorted octahedral coordination environment (Higgins & Ribbe, 1976; Speer & Gibbs, 1976).

With regard to the mechanism of phase transition and the nature of an intermediate polymorph between 490 and 825 K, the phase transition to the ordered titanite structure has been studied by numerous authors (Ghose et al., 1991; Salje et al., 1993; Zhang et al., 1995; Kek et al., 1997; Hayward et al., 2000; Malcherek et al., 2001; Malcherek, 2001). Analogous phase transitions also occur in structural analogues containing other d⁰ transition elements (Malcherek et al., 2004; Malcherek, 2007). The macroscopic formation of the ordered titanite structure is however suppressed in most natural titanite crystals which invariably contain impurity atoms such as Al or Fe (Higgins & Ribbe, 1976; Oberti et al., 1991). One well known example of a cation substitution that suppresses the out-of-centre displacement of the octahedrally coordinated cation is that of Sn for Ti in the titanite–malayaite solid solution (Kunz et al., 1997), which is a consequence of the absence of the second-order Jahn–Teller effect in the SnO₆ octahedron (Kunz & Brown, 1995). When studying the computational prediction of the ordered titanite phase using density functional perturbation theory (DFPT), Malcherek & Fischer (2018) used malayaite as a reference system for the undistorted C2/c crystal structure. However, the calculated phonon dispersion of malayaite showed that several modes that are dominated by motion of the Ca atom are unstable at various wavevectors (Malcherek & Fischer, 2018). This prompted us to investigate the low-temperature crystal structure of malayaite in order to test whether any transition to a lower-symmetry structure occurs.

The Ca atom occupies interstices in the framework of corner-sharing SnO₆ octahedra and SiO₄ tetrahedra. At room temperature, the thermal displacement of Ca is strongly anisotropic (Higgins & Ribbe, 1977; Groat et al., 1996), with its largest displacement amplitude extending subparallel to [001], i.e. the octahedral chain direction in the C2/c setting. Anomalies in the thermal expansion, in the temperature evolution of the Ca mean-square displacement as well as in the infrared and Raman spectra of malayaite have been observed near 500 K (Groat et al., 1996; Meyer et al., 1998; Zhang et al., 1999), but with no obvious change in symmetry occurring at this temperature. Malayaite is further known to undergo a transition to triclinic symmetry at a pressure of 4.95 GPa, accompanied by an increase of the Ca coordination number from seven to eight (Rath et al., 2003). Structural analogues of malayaite, such as CaGe₂O₅ or CaZrGeO₅, exhibit temperature-driven monoclinic–triclinic polymorphism (Malcherek & Ellemann-Olesen, 2005). Even natural titanite, albeit Ta- and Al-rich, has been observed in triclinic symmetry (Lussier et al., 2009), possibly driven by cation ordering. In the following we will describe another distortion of the malayaite structure that occurs at low temperatures and involves long-range modulation of the monoclinic malayaite structure.

2. Experimental and computational methods

X-ray diffraction measurements of a natural single crystal of malayaite have been carried out at the P24 synchrotron beamline of PETRAIII/DESY in Hamburg, Germany. The temperature of the crystal was controlled using a Cryocool-LT He gas-stream cooler. Synchrotron radiation with λ = 0.61992 Å was obtained using a water-cooled Si double-crystal monochromator. Diffraction data were collected in ϕ and ω scans at two detector positions on a four-circle kappa diffractometer (EH1). Scattered X-rays have been detected using a MARCCD165 detector. Integration, reduction and correction of the scattering data were performed using CrysAlisPRO (Rigaku Oxford Diffraction, 2015). Because of ice formation, diffraction data arising from four of the ω scans have been omitted from the final low-temperature data set (Table 1). Structure refinement has been conducted using Jana2006 (Petříček et al., 2014).

Table 1
Experimental details

Crystal data
Chemical formula	CaO5SiSn	CaO5SiSn
Mr	266.87	266.87
Temperature (K)	20	298
Crystal system, space group	Monoclinic,	C2/c
Wavevectors		–
a (Å)	6.6663 (3)	6.6667 (2)
b (Å)	8.8954 (4)	8.8934 (3)
c (Å)	7.1475 (3)	7.1520 (3)
β (°)	113.405	113.323 (3)
V (Å^3)	388.97 (3)	389.39 (3)
Z	4	4
Radiation type	X-ray, λ = 0.61992 Å	X-ray, λ = 0.61992 Å
μ (mm^−1)	5.53	5.52
Crystal size (mm)	0.16 × 0.09 × 0.09	0.16 × 0.09 × 0.09
Data collection
Diffractometer	Four-circle kappa	Four-circle kappa
Absorption correction	Multi-scan	Multi-scan
Tmin, Tmax	0.742, 1	0.754, 1
No. of measured, independent and observed [I > 3σ(I)] reflections	26 411, 7250, 5161	11 739, 2748, 2651
Rint	0.031	0.019
(sinθ/λ)max (Å^−1)	1.251	1.251
Refinement
R [F^2 > 3σ(F^2)], wR (F^2), S	0.044, 0.204, 1.30	0.026, 0.113, 1.06
R [F^2 > 3σ(F^2)], wR (F^2), S main reflections	0.039, 0.183	0.026, 0.113
R [F^2 > 3σ(F^2)], wR (F^2), S satellites	0.092, 0.26	-
No. of main reflections	2147	2651
No. of satellites	5101	0
No. of parameters	68	41
Δρmax, Δρmin (e Å^−3)	1.48, −2.04	0.7, −0.67

The investigated malayaite crystal is from the El Hammam mine, Morocco (Sonnet & Verkaeren, 1989). The sample material has been characterized by electron microprobe analysis, yielding an average stoichiometry of Ca(Sn_0.97Ti_0.03)SiO₅, with a very small, spatially inhomogeneous Ti⁴⁺ admixture.

First-principles calculations were performed by means of variational DFPT (Gonze, 1997; Gonze & Lee, 1997) as implemented in the CASTEP computer code (Clark et al., 2005; Refson et al., 2006). Details of these calculations are described by Malcherek & Fischer (2018). The plane-wave basis-set cut-off was set to 1200 eV. Norm-conserving pseudopotentials from the Bennett & Rappe pseudopotential library (Bennett, 2012), generated using the OPIUM code (Rappe et al., 1990), have been employed. An irreducible set of 16 k-points in the Brillouin zone (BZ) has been sampled. The Monkhorst–Pack mesh was 4 × 4 × 3. Phonon calculations were conducted with the zero-pressure optimized crystal structure. Calculations for the base-centred lattice were carried out using the reduced cell with transformed cell parameters a_r = b_r ≠ c_r = c, α′ = β′ ≠ γ′.

In the following, results of these calculations are reported in the conventional C-centred setting. A 2 × 2 × 2 mesh of q vectors was used to calculate the phonon dispersion. The exchange-correlation (XC) energy contributions have been treated in the generalized gradient approximation (GGA) using the PBE and PBEsol functionals (Perdew et al., 1996, 2008).

3. Results

Fig. 1 shows the calculated phonon dispersion of malayaite based on the two GGA approximations PBE and PBEsol. It is noteworthy that, unlike similar calculations made for titanite (Malcherek & Fischer, 2018), the two functionals yield very similar features, indicating that the results are not heavily dependent on the choice of functional. However, with PBEsol, especially frequencies in the Si–O stretching region above 800 cm⁻¹ are systematically higher than frequencies obtained with the PBE approximation, due to the smaller volume overestimation calculated with PBEsol (Table 2). On the other hand, this tendency is reversed for the lowest calculated frequencies, where PBEsol yields systematically lower frequencies than PBE. Two at least partially unstable phonon mode branches are indicated in malayaite, plotted with negative frequencies in Fig. 1. Both modes are dominated by motion of the Ca atoms parallel to [001]. While some of the details for the lowest-frequency range seem to depend on the choice of XC functional, the Raman active B_g mode has mostly imaginary frequency along the path section A-Γ-Y-V-Y-Γ, with the largest modulus located between Γ and Y, parallel to b^* [cf. the inset of Fig. 1 and Malcherek & Fischer (2018) concerning path details] in both XC approximations. Compared with this, the infrared active B_u mode is stable for most wavevectors, with the exception of those approaching the Y special point. This instability is enhanced with the PBEsol XC functional, which also predicts imaginary frequency for the transverse optical (TO) mode at the Γ point, due to larger LO/TO (LO = longitudinal optical) splitting compared with the PBE result. The type of motion associated with these two B_g and B_u modes is pictured in Fig. 2 for the Γ point, as well as for the BZ boundary point Y (0, 1, 0).

Table 2
Calculated and measured lattice parameters of malayaite

	a (Å)	b (Å)	c (Å)	β (°)	V (Å^3)	V/V298K − 1
PBE	6.8011	8.9864	7.3112	113.9	408.513	0.049
PBEsol	6.7095	8.9369	7.2291	113.69	396.96	0.019
Experimental, 298 K	6.6667 (1)	8.8934 (1)	7.1520 (1)	113.323 (1)	389.39 (1)	0
Experimental, 20 K	6.6663 (3)	8.8954 (4)	7.1475 (3)	113.405 (5)	388.97 (3)	−0.001

Figure 1 Calculated phonon dispersion of malayaite. Imaginary phonon frequencies of the unstable modes are shown in the real negative wavenumber range. The inset shows the location of special points and path details for the section A-Γ-Y-V-Y-Γ relative to the BZ boundary (green outline).

Figure 2 Crystal structure of malayaite in projection along [100] (a) and distortions caused by low- or imaginary-frequency Bg and Bu phonon modes (b)–(e). Green arrows indicate the relative motion of Ca atoms. The amplitude of the displacements is exaggerated for clarity. Si atoms are shown in light brown, Sn in grey, Ca in green and O in red.

In light of the existence of a high-pressure phase transition to a triclinic malayaite polymorph and similar, but temperature-driven monoclinic to triclinic transitions in isostructural compounds, one plausible way to overcome the encountered dynamic instabilities is a structural transition to triclinic symmetry and space group , which is a maximal subgroup of C2/c. The unit cell of this triclinic structure is the reduced cell of the C2/c structure with possible distortions. DFPT calculations based on a malayaite crystal structure relaxed in triclinic symmetry did indeed render all phonon modes stable. However, the actual low-temperature crystal structure of malayaite turned out to be different, as shown in the following.

Fig. 3 depicts a section of the hk7 layer of reciprocal space measured at a temperature of 20 K. Satellite reflections (m = 1, −1) with a modulation vector of q = 0.2606 (8)b^* can be distinguished from the main reflections with m = 0 in this and other layers of reciprocal space. Only first-order satellite reflections are observed. The position of these satellites relative to the Γ and Y points of the first BZ (Fig. 3) is indeed close to the calculated shallow `minimum' of imaginary phonon frequency of the lowest-frequency B_g mode (indicated by an arrow in Fig. 1). That the calculated phonon instability matches the observed structure modulation rather well is further indicated by the fact that the Ca atoms of the refined modulated structure at 20 K do show the largest displacements, directed parallel to [001] (Fig. 4). The good agreement of these experimental observations with the dynamic structure modulations induced by the B_g mode is demonstrated in Fig. 5, where the refined modulated structure is superimposed with a snapshot of the calculated phonon with wavevector (0, 0.3, 0), indicating a good match of both structure projections.

Figure 3 Reconstructed intensity in a section of the hk7m reciprocal-lattice plane, showing fundamental (m = 0) and first-order satellite diffraction maxima (m = 1, −1). The border of the first Brillouin zone of the C2/c parent structure is outlined in green at the 3,−5,7,0 reciprocal-lattice point.

Figure 4 Atomic displacement along [001] as a function of the modulation coordinate t.

Figure 5 Superposition of the malayaite crystal structure in projection along [100], obtained as a snapshot of the structural distortions induced by the unstable Bg phonon (transparent, framed foreground) and the modulated crystal structure refined against the 20 K diffraction data (background). Atomic displacements have been amplified by a factor of five for clarity. Compare Fig. 2 for orientation and colour coding.

Thus the observed incommensurate structure modulation can be understood as a result of softening of the dynamic displacements associated with this phonon mode, i.e. static displacements of the atoms according to a single irreducible representation. The predicted instability of the phonon mode in the 0 K approximation supports the development of such static displacements at a certain, yet unknown critical temperature. The wavelength of the modulation at 20 K amounts to approximately 4b.

The resulting structure is described in the C2/c(0β0)s0 superspace group (de Wolff et al., 1981; Janssen et al., 2004). Using the parent space group and the modulation vector as input with the Isosubgroup utility (Stokes et al., 2016, 2019), C2/c(0β0)s0 appears as a possible isotropy subgroup of C2/c, with LD2 as the active irreducible representation. The symmetry of malayaite remains monoclinic at 20 K. A few, low-intensity violations of the diffraction conditions for the c-glide plane appear above the 3σ(I) level in the h0l layer. These violations however appear irrespective of temperature and are likely caused by multiple scattering effects. No significant deviation from the monoclinic metric is observed.

Even at 20 K the Ca displacement tensor remains strongly anisotropic. The largest eigenvalue of the harmonic displacement tensor is about four times larger than the other two eigenvalues (0.0132, 0.0029 and 0.0030 Ų, respectively). This anisotropy is however smaller and more symmetric than for the room-temperature displacement tensor [0.0412, 0.0062 and 0.0037 Ų, also compare Higgins & Ribbe (1977)].

There is very little contraction of the unit-cell volume occurring down to 20 K (Table 2). a is almost constant and b even slightly expands with respect to the room-temperature value, while c contracts by a mere 0.0045 Å. The observed slight increase in the β angle continues the trend observed by Groat et al. (1996) at higher temperatures.

The Ca—O distances vary most strongly due to the structural modulation. This does predominantly affect the Ca—O3 distances subparallel to the octahedral chain direction (corresponding to [001] in the present setting), which vary between 2.7088 (6) and 2.7587 (6) Å, following the Ca displacement depicted in Fig. 4. The respective room-temperature bond distance is 2.7413 (5) Å.

It is instructive to compare these Ca—O bond-length modulations with the Ca—O bond-length changes induced by the transition to triclinic symmetry observed at high-pressure conditions by Rathet al. (2003) (Fig. 6). At 5.77 GPa, the two Ca—O3 distances that are subparallel to the octahedral chain direction amount to 2.69 (1) and 2.743 (1) Å. The bond-length difference of 0.05 Å induced by the shift of the Ca atom is almost identical to the modulation range of the Ca—O3 bonds in the structure at 20 K. This emphasizes that the modulation described here and the triclinic distortion are induced by instability of the same type of atomic motion, with a finite wavevector (LD, Fig. 5) in the former and a zero wavevector [Γ, Fig. 2(b)] in the latter case.

Figure 6 Deviation of bond distances Ca—O31, 2 subparallel to [001] from their average, for the modulated crystal structure at T = 20 K (solid lines), compared with the corresponding deviation for the triclinic structure at 5.77 GPa (Rath et al., 2003) (dashed lines). The inset shows the Ca coordination in projection parallel to a^*.

The occurrence of the triclinically distorted structure in compounds of general composition CaMOXO₄ has been linked to a critical monoclinic distortion of the framework of octahedral chains and XO₄ tetrahedra (Malcherek & Ellemann-Olesen, 2005). As the monoclinic β angle does not decrease with falling temperature (Table 2), such a critical monoclinic distortion is only attained in malayaite under high-pressure conditions, where the decrease of β below 113° correlates with the volume compression.

Based on bond-valence calculations with parameters taken from Brese & O'Keeffe (1991), the room-temperature structure of malayaite does exhibit overbonding of Sn and O1, due to a rather short Sn—O1 bond distance of 1.9470 (3) Å. This overbonding persists at 20 K, where the modulation however hardly affects the Sn—O1 bond distance.

4. Conclusions

On the basis of the computational results, the crystal structure of malayaite at 20 K appears to be modulated by a soft B_g optic phonon, leading to a transverse modulation of the Ca position with a period of close to 34 Å along [010]. The displacement is most pronounced along [001], i.e. the direction of the octahedral chains in the C2/c setting. While, to the best of the authors' knowledge, no structure determination at similarly low temperatures has so far been conducted for titanite, it is unlikely that similar modulations occur in titanite, as the available phonon calculations for this compound (Gutmann et al., 2013; Malcherek & Fischer, 2018) do not indicate any similar instabilities for the ordered P2₁/c structure. The titanite phonon modes corresponding to the unstable modes of malayaite are stable in the GGA approximation, albeit at low frequency, even in the C2/c symmetry (Malcherek & Fischer, 2018). The second-order Jahn–Teller effect associated with the Ti atoms dominates in titanite, leading to the formation of a fully ordered structure that involves an ordered arrangement of short and long Ti—O bonds, modifying the position and dynamics of the Ca atoms in its wake. In malayaite this static distortion of the structural framework is absent and the monoclinic base-centred structure is retained to the lowest temperatures, with the lowest-frequency mode of the Ca atoms eventually softening to form the modulated structure. The exact temperature of the phase transition to this modulated structure remains to be determined.

Supporting information

Computing details

For both structures, data collection: CrysAlis PRO 1.171.38.46 (Rigaku OD, 2015); cell refinement: CrysAlis PRO 1.171.38.46 (Rigaku OD, 2015); data reduction: CrysAlis PRO 1.171.38.46 (Rigaku OD, 2015); program(s) used to refine structure: Jana2006; molecular graphics: Jmol.

(I)

Crystal data

CaO5SiSn	F(000) = 496
Mr = 266.9	Dx = 4.557 Mg m^−3
Monoclinic, C2/c(0β0)s0†	Synchrotron radiation, λ = 0.61992 Å
q = 0.260600b*	Cell parameters from 7943 reflections
a = 6.6663 (3) Å	θ = 2.7–51.0°
b = 8.8954 (4) Å	µ = 5.53 mm^−1
c = 7.1475 (3) Å	T = 20 K
β = 113.405 (5)°	Irregular, yellow
V = 388.97 (3) Å^3	0.16 × 0.09 × 0.09 mm
Z = 4

† Symmetry operations: (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.

Data collection

Esperanto-CrysAlisPro-abstract goniometer imported esperanto images diffractometer	7250 independent reflections
Radiation source: synchrotron	5161 reflections with I > 3σ(I)
Synchrotron monochromator	Rint = 0.031
ω and φ scans	θmax = 50.9°, θmin = 2.8°
Absorption correction: multi-scan CrysAlisPro 1.171.38.46 (Rigaku Oxford Diffraction, 2015) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	h = −13→13
Tmin = 0.742, Tmax = 1	k = −19→19
26411 measured reflections	l = −17→16

Refinement

Refinement on F^2	0 constraints
R[F^2 > 2σ(F^2)] = 0.044	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.01I^2)
wR(F^2) = 0.204	(Δ/σ)max = 0.001
S = 1.30	Δρmax = 1.48 e Å^−3
7250 reflections	Δρmin = −2.04 e Å^−3
68 parameters	Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 9000 (1200)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn	0	0	0	0.00218 (5)
Si	0	0.68161 (8)	0.25	0.00251 (8)
Ca	0	0.33686 (4)	0.25	0.00636 (6)
O1	0	0.08680 (8)	0.25	0.00419 (13)
O2	0.32451 (8)	0.06735 (6)	0.08692 (6)	0.00470 (10)
O3	0.39036 (8)	0.28755 (6)	0.37253 (6)	0.00441 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn	0.00195 (7)	0.00243 (7)	0.00197 (6)	−0.000036 (7)	0.00059 (4)	−0.000037 (7)
Si	0.00203 (12)	0.00273 (16)	0.00246 (9)	0	0.00057 (7)	0
Ca	0.00311 (9)	0.00301 (9)	0.01036 (8)	0	−0.00008 (6)	0
O1	0.0063 (2)	0.0032 (2)	0.00339 (13)	0	0.00219 (12)	0
O2	0.00358 (15)	0.00427 (16)	0.00513 (11)	−0.00070 (10)	0.00053 (9)	−0.00116 (9)
O3	0.00412 (15)	0.00376 (18)	0.00522 (12)	−0.00012 (9)	0.00172 (9)	−0.00076 (9)

Geometric parameters (Å, º)

	Average	Minimum	Maximum
Sn—Si^i	3.3487 (6)	3.3449 (6)	3.3526 (6)
Sn—Si^ii	3.4901 (8)	3.4871 (8)	3.4932 (8)
Sn—Si^iii	3.3487 (6)	3.3449 (6)	3.3526 (6)
Sn—Si^iv	3.4901 (8)	3.4871 (8)	3.4932 (8)
Sn—Ca	3.4888 (3)	3.4758 (3)	3.5021 (3)
Sn—Ca^ii	3.4173 (8)	3.4132 (8)	3.4213 (8)
Sn—Ca^v	3.4888 (3)	3.4758 (3)	3.5021 (3)
Sn—Ca^iv	3.4173 (8)	3.4132 (8)	3.4213 (8)
Sn—O1	1.9466 (5)	1.9451 (5)	1.9480 (5)
Sn—O1^v	1.9466 (5)	1.9451 (5)	1.9480 (5)
Sn—O2	2.0873 (8)	2.0845 (8)	2.0902 (8)
Sn—O2^v	2.0873 (8)	2.0845 (8)	2.0902 (8)
Sn—O3^vi	2.0992 (5)	2.0982 (5)	2.1002 (5)
Sn—O3^vii	2.0992 (5)	2.0982 (5)	2.1002 (5)
Si—Ca	3.0669 (8)	3.0667 (8)	3.0670 (8)
Si—O1^viii	3.4382 (9)	3.4328 (9)	3.4436 (9)
Si—O1^ix	3.4382 (9)	3.4328 (9)	3.4436 (9)
Si—O2^viii	1.6363 (7)	1.6348 (7)	1.6378 (7)
Si—O2^x	1.6362 (7)	1.6348 (7)	1.6378 (7)
Si—O2^iii	3.3656 (8)	3.3555 (8)	3.3756 (8)
Si—O2^xi	3.3656 (8)	3.3555 (8)	3.3756 (8)
Si—O3^viii	1.6425 (8)	1.6418 (8)	1.6432 (8)
Si—O3^x	1.6425 (8)	1.6418 (8)	1.6432 (8)
Ca—O1	2.2245 (8)	2.2244 (8)	2.2246 (8)
Ca—O2^viii	2.4183 (7)	2.4148 (7)	2.4219 (7)
Ca—O2^x	2.4182 (7)	2.4148 (7)	2.4219 (7)
Ca—O2^xii	3.1828 (7)	3.1344 (7)	3.2319 (7)
Ca—O2^xiii	3.1834 (7)	3.1344 (7)	3.2319 (7)
Ca—O3	2.4333 (9)	2.4317 (9)	2.4352 (9)
Ca—O3^xiv	2.4333 (9)	2.4317 (9)	2.4352 (9)
Ca—O3^xv	2.7335 (6)	2.7082 (6)	2.7587 (6)
Ca—O3^vii	2.7333 (6)	2.7082 (6)	2.7587 (6)
O1—O2	2.8411 (9)	2.8389 (9)	2.8432 (9)
O1—O2^xiv	2.8410 (9)	2.8389 (9)	2.8432 (9)
O1—O2^v	2.8671 (8)	2.8668 (8)	2.8675 (8)
O1—O2^xvi	2.8671 (8)	2.8668 (8)	2.8675 (8)
O1—O3	2.9861 (10)	2.9813 (10)	2.9909 (10)
O1—O3^xvii	2.9826 (9)	2.9811 (9)	2.9840 (9)
O1—O3^xiv	2.9862 (10)	2.9813 (10)	2.9909 (10)
O1—O3^vi	2.9826 (9)	2.9811 (9)	2.9840 (9)
O1—O3^xv	2.7379 (7)	2.7350 (7)	2.7407 (7)
O1—O3^vii	2.7378 (7)	2.7350 (7)	2.7407 (7)
O2—O2^xviii	2.5644 (8)	2.5644 (8)	2.5644 (8)
O2—O2^xix	3.2808 (10)	3.2756 (10)	3.2862 (10)
O2—O2^xii	3.4798 (8)	3.4581 (8)	3.5019 (8)
O2—O3	2.7360 (8)	2.7326 (8)	2.7394 (8)
O2—O3^xviii	2.6639 (9)	2.6583 (9)	2.6696 (9)
O2—O3^vi	2.9428 (9)	2.9383 (9)	2.9473 (9)
O2—O3^xii	3.2809 (7)	3.2692 (7)	3.2929 (7)
O2—O3^vii	2.9778 (10)	2.9769 (10)	2.9786 (10)
O3—O3^xviii	2.6906 (10)	2.6906 (10)	2.6906 (10)
O3—O3^xv	3.1587 (10)	3.1550 (10)	3.1624 (10)
Si^i—Sn—Si^ii	108.705 (10)	108.593 (10)	108.819 (10)
Si^i—Sn—Si^iii	179.9 (2)	179.869 (9)	180.0 (5)
Si^i—Sn—Si^iv	71.295 (10)	71.182 (10)	71.406 (10)
Si^i—Sn—Ca	116.947 (8)	116.497 (8)	117.392 (8)
Si^i—Sn—Ca^ii	64.444 (6)	64.152 (6)	64.731 (6)
Si^i—Sn—Ca^v	63.053 (8)	62.511 (8)	63.600 (8)
Si^i—Sn—Ca^iv	115.556 (6)	115.284 (6)	115.834 (6)
Si^i—Sn—O1	81.12 (2)	81.01 (2)	81.24 (2)
Si^i—Sn—O1^v	98.88 (2)	98.70 (2)	99.06 (2)
Si^i—Sn—O2	107.675 (16)	107.415 (16)	107.930 (16)
Si^i—Sn—O2^v	72.325 (16)	72.088 (16)	72.568 (16)
Si^i—Sn—O3^vi	23.197 (19)	23.071 (19)	23.320 (19)
Si^i—Sn—O3^vii	156.803 (19)	156.663 (19)	156.946 (19)
Si^ii—Sn—Si^iii	71.295 (10)	71.182 (10)	71.406 (10)
Si^ii—Sn—Si^iv	180.0 (5)	180.0 (5)	180.0 (5)
Si^ii—Sn—Ca	62.258 (9)	62.101 (9)	62.417 (9)
Si^ii—Sn—Ca^ii	52.705 (12)	52.679 (12)	52.735 (12)
Si^ii—Sn—Ca^v	117.742 (9)	117.631 (9)	117.851 (9)
Si^ii—Sn—Ca^iv	127.295 (12)	127.228 (12)	127.363 (12)
Si^ii—Sn—O1	72.219 (15)	72.021 (15)	72.421 (15)
Si^ii—Sn—O1^v	107.781 (15)	107.593 (15)	107.965 (15)
Si^ii—Sn—O2	17.954 (18)	17.836 (18)	18.070 (18)
Si^ii—Sn—O2^v	162.046 (18)	161.904 (18)	162.193 (18)
Si^ii—Sn—O3^vi	95.590 (18)	95.348 (18)	95.836 (18)
Si^ii—Sn—O3^vii	84.410 (18)	84.167 (18)	84.649 (18)
Si^iii—Sn—Si^iv	108.705 (10)	108.593 (10)	108.819 (10)
Si^iii—Sn—Ca	63.053 (8)	62.511 (8)	63.600 (8)
Si^iii—Sn—Ca^ii	115.556 (6)	115.284 (6)	115.834 (6)
Si^iii—Sn—Ca^v	116.947 (8)	116.497 (8)	117.392 (8)
Si^iii—Sn—Ca^iv	64.444 (6)	64.152 (6)	64.731 (6)
Si^iii—Sn—O1	98.88 (2)	98.70 (2)	99.06 (2)
Si^iii—Sn—O1^v	81.12 (2)	81.01 (2)	81.24 (2)
Si^iii—Sn—O2	72.325 (16)	72.088 (16)	72.568 (16)
Si^iii—Sn—O2^v	107.675 (16)	107.415 (16)	107.930 (16)
Si^iii—Sn—O3^vi	156.803 (19)	156.663 (19)	156.946 (19)
Si^iii—Sn—O3^vii	23.197 (19)	23.071 (19)	23.320 (19)
Si^iv—Sn—Ca	117.742 (9)	117.631 (9)	117.851 (9)
Si^iv—Sn—Ca^ii	127.295 (12)	127.228 (12)	127.363 (12)
Si^iv—Sn—Ca^v	62.258 (9)	62.101 (9)	62.417 (9)
Si^iv—Sn—Ca^iv	52.705 (12)	52.679 (12)	52.735 (12)
Si^iv—Sn—O1	107.781 (15)	107.593 (15)	107.965 (15)
Si^iv—Sn—O1^v	72.219 (15)	72.021 (15)	72.421 (15)
Si^iv—Sn—O2	162.046 (18)	161.904 (18)	162.193 (18)
Si^iv—Sn—O2^v	17.954 (18)	17.836 (18)	18.070 (18)
Si^iv—Sn—O3^vi	84.410 (18)	84.167 (18)	84.649 (18)
Si^iv—Sn—O3^vii	95.590 (18)	95.348 (18)	95.836 (18)
Ca—Sn—Ca^ii	107.182 (7)	106.787 (6)	107.565 (6)
Ca—Sn—Ca^v	179.49 (4)	179.192 (6)	180.0 (5)
Ca—Sn—Ca^iv	72.818 (6)	72.438 (6)	73.210 (6)
Ca—Sn—O1	35.82 (2)	35.46 (2)	36.19 (2)
Ca—Sn—O1^v	144.18 (2)	143.66 (2)	144.69 (2)
Ca—Sn—O2	79.157 (17)	78.880 (17)	79.433 (17)
Ca—Sn—O2^v	100.843 (17)	100.708 (17)	100.979 (17)
Ca—Sn—O3^vi	128.447 (15)	128.050 (15)	128.841 (15)
Ca—Sn—O3^vii	51.553 (15)	51.151 (15)	51.958 (15)
Ca^ii—Sn—Ca^v	72.818 (7)	72.438 (7)	73.210 (7)
Ca^ii—Sn—Ca^iv	179.9 (2)	179.859 (6)	180.0 (5)
Ca^ii—Sn—O1	92.533 (14)	92.044 (14)	93.012 (14)
Ca^ii—Sn—O1^v	87.467 (14)	86.988 (14)	87.957 (14)
Ca^ii—Sn—O2	44.434 (17)	44.361 (17)	44.507 (17)
Ca^ii—Sn—O2^v	135.566 (17)	135.400 (17)	135.733 (17)
Ca^ii—Sn—O3^vi	44.896 (17)	44.825 (17)	44.965 (17)
Ca^ii—Sn—O3^vii	135.104 (17)	135.069 (17)	135.141 (17)
Ca^v—Sn—Ca^iv	107.182 (7)	106.787 (6)	107.565 (6)
Ca^v—Sn—O1	144.18 (2)	143.66 (2)	144.69 (2)
Ca^v—Sn—O1^v	35.82 (2)	35.46 (2)	36.19 (2)
Ca^v—Sn—O2	100.843 (17)	100.708 (17)	100.979 (17)
Ca^v—Sn—O2^v	79.157 (17)	78.880 (17)	79.433 (17)
Ca^v—Sn—O3^vi	51.553 (15)	51.151 (15)	51.958 (15)
Ca^v—Sn—O3^vii	128.447 (15)	128.050 (15)	128.841 (15)
Ca^iv—Sn—O1	87.467 (14)	86.988 (14)	87.957 (14)
Ca^iv—Sn—O1^v	92.533 (14)	92.044 (14)	93.012 (14)
Ca^iv—Sn—O2	135.566 (17)	135.400 (17)	135.733 (17)
Ca^iv—Sn—O2^v	44.434 (17)	44.361 (17)	44.507 (17)
Ca^iv—Sn—O3^vi	135.104 (17)	135.069 (17)	135.141 (17)
Ca^iv—Sn—O3^vii	44.896 (17)	44.825 (17)	44.965 (17)
O1—Sn—O1^v	179.89 (16)	179.81 (3)	180.0 (5)
O1—Sn—O2	89.48 (2)	89.36 (2)	89.59 (2)
O1—Sn—O2^v	90.52 (2)	90.49 (2)	90.56 (2)
O1—Sn—O3^vi	94.91 (2)	94.82 (2)	95.01 (2)
O1—Sn—O3^vii	85.09 (2)	84.98 (2)	85.19 (2)
O1^v—Sn—O2	90.52 (2)	90.49 (2)	90.56 (2)
O1^v—Sn—O2^v	89.48 (2)	89.36 (2)	89.59 (2)
O1^v—Sn—O3^vi	85.09 (2)	84.98 (2)	85.19 (2)
O1^v—Sn—O3^vii	94.91 (2)	94.82 (2)	95.01 (2)
O2—Sn—O2^v	179.87 (14)	179.77 (2)	180.0 (5)
O2—Sn—O3^vi	89.32 (2)	89.19 (2)	89.46 (2)
O2—Sn—O3^vii	90.68 (2)	90.58 (2)	90.78 (2)
O2^v—Sn—O3^vi	90.68 (2)	90.58 (2)	90.78 (2)
O2^v—Sn—O3^vii	89.32 (2)	89.19 (2)	89.46 (2)
O3^vi—Sn—O3^vii	180.0 (5)	180.0 (5)	180.0 (5)
Sn^xx—Si—Sn^viii	108.706 (8)	108.611 (8)	108.801 (8)
Sn^xx—Si—Sn^xxi	64.497 (13)	64.497 (13)	64.497 (13)
Sn^xx—Si—Sn^x	117.532 (9)	117.434 (9)	117.631 (9)
Sn^xx—Si—Ca	147.747 (9)	147.073 (9)	148.430 (9)
Sn^xx—Si—O1^viii	114.389 (15)	114.237 (15)	114.543 (15)
Sn^xx—Si—O1^ix	90.114 (14)	89.997 (14)	90.230 (14)
Sn^xx—Si—O2^viii	107.26 (2)	106.72 (2)	107.81 (2)
Sn^xx—Si—O2^x	138.94 (3)	138.73 (3)	139.14 (3)
Sn^xx—Si—O2^iii	36.223 (12)	36.099 (12)	36.347 (12)
Sn^xx—Si—O2^xi	71.602 (16)	71.515 (16)	71.688 (16)
Sn^xx—Si—O3^viii	83.89 (3)	83.83 (3)	83.96 (3)
Sn^xx—Si—O3^x	30.22 (2)	30.07 (2)	30.38 (2)
Sn^viii—Si—Sn^xxi	117.532 (9)	117.434 (9)	117.631 (9)
Sn^viii—Si—Sn^x	124.85 (2)	124.85 (2)	124.85 (2)
Sn^viii—Si—Ca	62.429 (10)	62.318 (10)	62.535 (10)
Sn^viii—Si—O1^viii	32.624 (9)	32.623 (9)	32.624 (9)
Sn^viii—Si—O1^ix	127.96 (2)	127.91 (2)	128.02 (2)
Sn^viii—Si—O2^viii	23.16 (2)	23.00 (2)	23.31 (2)
Sn^viii—Si—O2^x	110.14 (3)	109.90 (3)	110.38 (3)
Sn^viii—Si—O2^iii	74.282 (11)	74.096 (11)	74.469 (11)
Sn^viii—Si—O2^xi	152.271 (16)	152.033 (16)	152.511 (16)
Sn^viii—Si—O3^viii	90.10 (2)	90.01 (2)	90.20 (2)
Sn^viii—Si—O3^x	121.961 (17)	121.888 (17)	122.033 (17)
Sn^xxi—Si—Sn^x	108.706 (8)	108.611 (8)	108.801 (8)
Sn^xxi—Si—Ca	147.755 (9)	147.073 (9)	148.430 (9)
Sn^xxi—Si—O1^viii	90.113 (14)	89.997 (14)	90.230 (14)
Sn^xxi—Si—O1^ix	114.390 (15)	114.237 (15)	114.543 (15)
Sn^xxi—Si—O2^viii	138.94 (3)	138.73 (3)	139.14 (3)
Sn^xxi—Si—O2^x	107.27 (2)	106.72 (2)	107.81 (2)
Sn^xxi—Si—O2^iii	71.602 (16)	71.515 (16)	71.688 (16)
Sn^xxi—Si—O2^xi	36.223 (12)	36.099 (12)	36.347 (12)
Sn^xxi—Si—O3^viii	30.22 (2)	30.07 (2)	30.38 (2)
Sn^xxi—Si—O3^x	83.89 (3)	83.83 (3)	83.96 (3)
Sn^x—Si—Ca	62.427 (10)	62.318 (10)	62.535 (10)
Sn^x—Si—O1^viii	127.96 (2)	127.91 (2)	128.02 (2)
Sn^x—Si—O1^ix	32.624 (9)	32.623 (9)	32.624 (9)
Sn^x—Si—O2^viii	110.14 (3)	109.90 (3)	110.38 (3)
Sn^x—Si—O2^x	23.15 (2)	23.00 (2)	23.31 (2)
Sn^x—Si—O2^iii	152.271 (16)	152.033 (16)	152.511 (16)
Sn^x—Si—O2^xi	74.283 (11)	74.096 (11)	74.469 (11)
Sn^x—Si—O3^viii	121.961 (17)	121.888 (17)	122.033 (17)
Sn^x—Si—O3^x	90.10 (2)	90.01 (2)	90.20 (2)
Ca—Si—O1^viii	75.804 (17)	75.366 (16)	76.235 (17)
Ca—Si—O1^ix	75.798 (17)	75.366 (16)	76.235 (17)
Ca—Si—O2^viii	51.59 (3)	51.46 (3)	51.72 (3)
Ca—Si—O2^x	51.59 (3)	51.46 (3)	51.72 (3)
Ca—Si—O2^iii	131.567 (13)	131.148 (13)	131.990 (13)
Ca—Si—O2^xi	131.571 (13)	131.148 (13)	131.990 (13)
Ca—Si—O3^viii	125.01 (3)	124.36 (3)	125.66 (3)
Ca—Si—O3^x	125.01 (3)	124.36 (3)	125.66 (3)
O1^viii—Si—O1^ix	151.60 (3)	151.60 (3)	151.60 (3)
O1^viii—Si—O2^viii	55.17 (3)	54.93 (3)	55.40 (3)
O1^viii—Si—O2^x	105.45 (3)	105.36 (3)	105.55 (3)
O1^viii—Si—O2^iii	79.349 (16)	79.056 (16)	79.641 (16)
O1^viii—Si—O2^xi	120.687 (18)	120.445 (18)	120.930 (18)
O1^viii—Si—O3^viii	60.26 (2)	60.19 (2)	60.34 (2)
O1^viii—Si—O3^x	141.03 (3)	140.98 (3)	141.08 (3)
O1^ix—Si—O2^viii	105.45 (3)	105.36 (3)	105.55 (3)
O1^ix—Si—O2^x	55.16 (3)	54.93 (3)	55.40 (3)
O1^ix—Si—O2^iii	120.687 (18)	120.445 (18)	120.930 (18)
O1^ix—Si—O2^xi	79.349 (16)	79.056 (16)	79.641 (16)
O1^ix—Si—O3^viii	141.03 (3)	140.98 (3)	141.08 (3)
O1^ix—Si—O3^x	60.26 (2)	60.19 (2)	60.34 (2)
O2^viii—Si—O2^x	103.19 (5)	103.18 (5)	103.19 (5)
O2^viii—Si—O2^iii	80.09 (2)	79.58 (2)	80.62 (2)
O2^viii—Si—O2^xi	175.13 (3)	174.83 (3)	175.43 (3)
O2^viii—Si—O3^viii	113.12 (3)	112.98 (3)	113.25 (3)
O2^viii—Si—O3^x	108.68 (3)	108.28 (3)	109.08 (3)
O2^x—Si—O2^iii	175.13 (3)	174.83 (3)	175.43 (3)
O2^x—Si—O2^xi	80.10 (2)	79.58 (2)	80.62 (2)
O2^x—Si—O3^viii	108.68 (3)	108.28 (3)	109.08 (3)
O2^x—Si—O3^x	113.11 (3)	112.98 (3)	113.25 (3)
O2^iii—Si—O2^xi	96.86 (2)	96.86 (2)	96.86 (2)
O2^iii—Si—O3^viii	72.85 (3)	72.74 (3)	72.97 (3)
O2^iii—Si—O3^x	62.19 (3)	61.87 (3)	62.52 (3)
O2^xi—Si—O3^viii	62.19 (3)	61.87 (3)	62.52 (3)
O2^xi—Si—O3^x	72.85 (3)	72.74 (3)	72.97 (3)
O3^viii—Si—O3^x	109.98 (5)	109.98 (5)	109.98 (5)
Sn—Ca—Sn^viii	107.180 (6)	106.744 (6)	107.605 (6)
Sn—Ca—Sn^xiv	61.615 (7)	61.613 (7)	61.617 (7)
Sn—Ca—Sn^x	115.729 (6)	115.223 (6)	116.224 (6)
Sn—Ca—Si	149.199 (7)	147.962 (7)	150.423 (8)
Sn—Ca—O1	30.809 (11)	30.504 (11)	31.109 (11)
Sn—Ca—O2^viii	125.436 (14)	124.498 (14)	126.361 (14)
Sn—Ca—O2^x	151.240 (17)	150.504 (17)	151.954 (17)
Sn—Ca—O2^xii	76.570 (12)	76.010 (12)	77.129 (12)
Sn—Ca—O2^xiii	133.800 (14)	133.339 (14)	134.262 (15)
Sn—Ca—O3	79.160 (15)	78.732 (15)	79.580 (15)
Sn—Ca—O3^xiv	83.016 (16)	82.678 (16)	83.344 (16)
Sn—Ca—O3^xv	95.931 (16)	95.834 (16)	96.029 (16)
Sn—Ca—O3^vii	36.978 (12)	36.802 (12)	37.151 (12)
Sn^viii—Ca—Sn^xiv	115.724 (6)	115.223 (6)	116.224 (6)
Sn^viii—Ca—Sn^x	129.732 (12)	129.723 (12)	129.740 (12)
Sn^viii—Ca—Si	64.866 (7)	64.768 (7)	64.972 (7)
Sn^viii—Ca—O1	115.125 (12)	114.992 (12)	115.257 (12)
Sn^viii—Ca—O2^viii	37.176 (14)	37.091 (14)	37.264 (14)
Sn^viii—Ca—O2^x	94.389 (17)	94.219 (17)	94.559 (17)
Sn^viii—Ca—O2^xii	93.789 (12)	93.028 (12)	94.542 (12)
Sn^viii—Ca—O2^xiii	72.936 (11)	72.483 (11)	73.392 (11)
Sn^viii—Ca—O3	161.135 (18)	160.149 (18)	162.078 (19)
Sn^viii—Ca—O3^xiv	37.510 (14)	37.460 (14)	37.560 (14)
Sn^viii—Ca—O3^xv	120.720 (15)	119.630 (15)	121.828 (15)
Sn^viii—Ca—O3^vii	80.384 (13)	79.977 (13)	80.785 (13)
Sn^xiv—Ca—Sn^x	107.174 (6)	106.744 (6)	107.605 (6)
Sn^xiv—Ca—Si	149.186 (7)	147.962 (7)	150.423 (8)
Sn^xiv—Ca—O1	30.806 (11)	30.504 (11)	31.109 (11)
Sn^xiv—Ca—O2^viii	151.231 (17)	150.504 (17)	151.954 (17)
Sn^xiv—Ca—O2^x	125.427 (14)	124.498 (14)	126.361 (14)
Sn^xiv—Ca—O2^xii	133.803 (14)	133.339 (14)	134.262 (15)
Sn^xiv—Ca—O2^xiii	76.565 (12)	76.010 (12)	77.129 (12)
Sn^xiv—Ca—O3	83.011 (16)	82.678 (16)	83.344 (16)
Sn^xiv—Ca—O3^xiv	79.156 (15)	78.732 (15)	79.580 (15)
Sn^xiv—Ca—O3^xv	36.976 (12)	36.802 (12)	37.151 (12)
Sn^xiv—Ca—O3^vii	95.931 (16)	95.834 (16)	96.029 (16)
Sn^x—Ca—Si	64.868 (7)	64.768 (7)	64.972 (7)
Sn^x—Ca—O1	115.122 (12)	114.992 (12)	115.257 (12)
Sn^x—Ca—O2^viii	94.392 (17)	94.219 (17)	94.559 (17)
Sn^x—Ca—O2^x	37.177 (14)	37.091 (14)	37.264 (14)
Sn^x—Ca—O2^xii	72.942 (11)	72.483 (11)	73.392 (11)
Sn^x—Ca—O2^xiii	93.780 (12)	93.028 (12)	94.542 (12)
Sn^x—Ca—O3	37.511 (14)	37.460 (14)	37.560 (14)
Sn^x—Ca—O3^xiv	161.123 (18)	160.149 (18)	162.078 (19)
Sn^x—Ca—O3^xv	80.381 (13)	79.977 (13)	80.785 (13)
Sn^x—Ca—O3^vii	120.735 (15)	119.630 (15)	121.828 (15)
Si—Ca—O1	179.02 (3)	178.463 (14)	180.0 (5)
Si—Ca—O2^viii	32.020 (13)	31.974 (13)	32.064 (13)
Si—Ca—O2^x	32.020 (13)	31.974 (13)	32.064 (13)
Si—Ca—O2^xii	74.476 (13)	73.761 (13)	75.181 (13)
Si—Ca—O2^xiii	74.467 (13)	73.761 (13)	75.181 (13)
Si—Ca—O3	100.381 (16)	100.099 (16)	100.652 (16)
Si—Ca—O3^xiv	100.377 (16)	100.099 (16)	100.652 (16)
Si—Ca—O3^xv	113.878 (15)	112.865 (15)	114.902 (15)
Si—Ca—O3^vii	113.889 (15)	112.865 (15)	114.902 (15)
O1—Ca—O2^viii	147.969 (16)	147.278 (16)	148.627 (16)
O1—Ca—O2^x	147.962 (16)	147.278 (16)	148.627 (16)
O1—Ca—O2^xii	105.531 (18)	104.735 (18)	106.320 (18)
O1—Ca—O2^xiii	105.525 (18)	104.735 (18)	106.320 (18)
O1—Ca—O3	79.609 (19)	79.465 (19)	79.764 (19)
O1—Ca—O3^xiv	79.612 (19)	79.465 (19)	79.764 (19)
O1—Ca—O3^xv	66.113 (17)	65.689 (16)	66.536 (17)
O1—Ca—O3^vii	66.116 (17)	65.689 (16)	66.536 (17)
O2^viii—Ca—O2^x	64.039 (19)	64.037 (19)	64.042 (19)
O2^viii—Ca—O2^xii	70.20 (2)	69.46 (2)	70.93 (2)
O2^viii—Ca—O2^xiii	83.38 (2)	82.807 (19)	83.97 (2)
O2^viii—Ca—O3	124.73 (2)	124.04 (2)	125.40 (2)
O2^viii—Ca—O3^xiv	74.68 (2)	74.57 (2)	74.80 (2)
O2^viii—Ca—O3^xv	135.03 (2)	133.86 (2)	136.22 (2)
O2^viii—Ca—O3^vii	88.800 (18)	88.013 (18)	89.578 (18)
O2^x—Ca—O2^xii	83.39 (2)	82.807 (19)	83.97 (2)
O2^x—Ca—O2^xiii	70.19 (2)	69.46 (2)	70.93 (2)
O2^x—Ca—O3	74.68 (2)	74.57 (2)	74.80 (2)
O2^x—Ca—O3^xiv	124.72 (2)	124.04 (2)	125.40 (2)
O2^x—Ca—O3^xv	88.793 (18)	88.013 (18)	89.578 (18)
O2^x—Ca—O3^vii	135.04 (2)	133.86 (2)	136.22 (2)
O2^xii—Ca—O2^xiii	148.94 (2)	148.94 (2)	148.94 (2)
O2^xii—Ca—O3	70.044 (17)	69.424 (17)	70.654 (17)
O2^xii—Ca—O3^xiv	115.974 (17)	115.010 (17)	116.929 (17)
O2^xii—Ca—O3^xv	145.142 (17)	144.840 (17)	145.434 (17)
O2^xii—Ca—O3^vii	52.865 (17)	52.203 (17)	53.526 (17)
O2^xiii—Ca—O3	115.963 (17)	115.010 (17)	116.929 (17)
O2^xiii—Ca—O3^xiv	70.036 (17)	69.424 (17)	70.654 (17)
O2^xiii—Ca—O3^xv	52.856 (17)	52.203 (17)	53.526 (17)
O2^xiii—Ca—O3^vii	145.137 (17)	144.840 (17)	145.434 (17)
O3—Ca—O3^xiv	159.20 (3)	159.17 (3)	159.23 (3)
O3—Ca—O3^xv	75.12 (2)	74.75 (2)	75.49 (2)
O3—Ca—O3^vii	96.36 (2)	95.36 (2)	97.35 (2)
O3^xiv—Ca—O3^xv	96.35 (2)	95.36 (2)	97.35 (2)
O3^xiv—Ca—O3^vii	75.12 (2)	74.75 (2)	75.49 (2)
O3^xv—Ca—O3^vii	132.23 (2)	132.22 (2)	132.23 (2)
Sn—O1—Sn^xiv	133.26 (4)	133.26 (4)	133.26 (4)
Sn—O1—Si^xvii	116.794 (15)	116.701 (15)	116.888 (15)
Sn—O1—Si^ii	75.157 (16)	74.955 (16)	75.356 (16)
Sn—O1—Ca	113.37 (2)	112.71 (2)	114.03 (3)
Sn—O1—O2	47.279 (15)	47.201 (15)	47.357 (15)
Sn—O1—O2^xiv	129.05 (2)	128.65 (2)	129.46 (2)
Sn—O1—O2^v	46.718 (17)	46.639 (17)	46.798 (17)
Sn—O1—O2^xvi	107.83 (3)	107.45 (3)	108.21 (3)
Sn—O1—O3	100.88 (2)	100.61 (2)	101.14 (2)
Sn—O1—O3^xvii	90.28 (3)	90.14 (3)	90.42 (3)
Sn—O1—O3^xiv	106.604 (17)	106.550 (17)	106.657 (17)
Sn—O1—O3^vi	44.526 (17)	44.467 (17)	44.585 (17)
Sn—O1—O3^xv	165.74 (2)	165.29 (2)	166.19 (2)
Sn—O1—O3^vii	49.812 (16)	49.739 (16)	49.884 (16)
Sn^xiv—O1—Si^xvii	75.154 (16)	74.955 (16)	75.356 (16)
Sn^xiv—O1—Si^ii	116.796 (15)	116.701 (15)	116.888 (15)
Sn^xiv—O1—Ca	113.37 (2)	112.71 (2)	114.03 (3)
Sn^xiv—O1—O2	129.06 (2)	128.65 (2)	129.46 (2)
Sn^xiv—O1—O2^xiv	47.279 (15)	47.201 (15)	47.357 (15)
Sn^xiv—O1—O2^v	107.83 (3)	107.45 (3)	108.21 (3)
Sn^xiv—O1—O2^xvi	46.717 (17)	46.639 (17)	46.798 (17)
Sn^xiv—O1—O3	106.603 (17)	106.550 (17)	106.657 (17)
Sn^xiv—O1—O3^xvii	44.526 (17)	44.467 (17)	44.585 (17)
Sn^xiv—O1—O3^xiv	100.87 (2)	100.61 (2)	101.14 (2)
Sn^xiv—O1—O3^vi	90.28 (3)	90.14 (3)	90.42 (3)
Sn^xiv—O1—O3^xv	49.811 (16)	49.739 (16)	49.884 (16)
Sn^xiv—O1—O3^vii	165.73 (2)	165.29 (2)	166.19 (2)
Si^xvii—O1—Si^ii	151.60 (3)	151.60 (3)	151.60 (3)
Si^xvii—O1—Ca	75.802 (19)	75.484 (19)	76.120 (19)
Si^xvii—O1—O2	155.656 (19)	155.449 (19)	155.868 (19)
Si^xvii—O1—O2^xiv	28.210 (13)	28.115 (13)	28.309 (13)
Si^xvii—O1—O2^v	73.100 (18)	73.018 (18)	73.183 (18)
Si^xvii—O1—O2^xvi	121.69 (2)	121.42 (2)	121.96 (2)
Si^xvii—O1—O3	125.82 (3)	125.76 (3)	125.87 (3)
Si^xvii—O1—O3^xvii	82.43 (2)	82.33 (2)	82.53 (2)
Si^xvii—O1—O3^xiv	28.530 (16)	28.478 (16)	28.583 (16)
Si^xvii—O1—O3^vi	124.72 (2)	124.61 (2)	124.83 (2)
Si^xvii—O1—O3^xv	77.240 (19)	76.898 (19)	77.590 (19)
Si^xvii—O1—O3^vii	91.174 (19)	90.938 (19)	91.414 (19)
Si^ii—O1—Ca	75.801 (19)	75.484 (19)	76.120 (19)
Si^ii—O1—O2	28.212 (13)	28.115 (13)	28.309 (13)
Si^ii—O1—O2^xiv	155.660 (19)	155.449 (19)	155.868 (19)
Si^ii—O1—O2^v	121.69 (2)	121.42 (2)	121.96 (2)
Si^ii—O1—O2^xvi	73.101 (18)	73.018 (18)	73.183 (18)
Si^ii—O1—O3	28.531 (16)	28.478 (16)	28.583 (16)
Si^ii—O1—O3^xvii	124.72 (2)	124.61 (2)	124.83 (2)
Si^ii—O1—O3^xiv	125.82 (3)	125.76 (3)	125.87 (3)
Si^ii—O1—O3^vi	82.43 (2)	82.33 (2)	82.53 (2)
Si^ii—O1—O3^xv	91.179 (19)	90.938 (19)	91.414 (19)
Si^ii—O1—O3^vii	77.247 (19)	76.898 (19)	77.590 (19)
Ca—O1—O2	93.49 (2)	92.85 (2)	94.13 (2)
Ca—O1—O2^xiv	93.50 (2)	92.85 (2)	94.13 (2)
Ca—O1—O2^v	118.57 (2)	118.15 (2)	118.99 (2)
Ca—O1—O2^xvi	118.57 (2)	118.15 (2)	118.99 (2)
Ca—O1—O3	53.275 (17)	53.186 (17)	53.359 (17)
Ca—O1—O3^xvii	153.19 (2)	152.53 (2)	153.84 (2)
Ca—O1—O3^xiv	53.274 (17)	53.186 (17)	53.359 (17)
Ca—O1—O3^vi	153.18 (2)	152.53 (2)	153.84 (2)
Ca—O1—O3^xv	65.909 (19)	65.232 (19)	66.58 (2)
Ca—O1—O3^vii	65.903 (19)	65.232 (19)	66.58 (2)
O2—O1—O2^xiv	173.01 (3)	173.00 (3)	173.01 (3)
O2—O1—O2^v	94.00 (2)	93.89 (2)	94.10 (2)
O2—O1—O2^xvi	82.65 (2)	82.17 (2)	83.13 (2)
O2—O1—O3	55.940 (19)	55.829 (19)	56.049 (19)
O2—O1—O3^xvii	112.42 (3)	112.30 (3)	112.54 (3)
O2—O1—O3^xiv	129.27 (3)	129.12 (2)	129.42 (2)
O2—O1—O3^vi	60.65 (2)	60.56 (2)	60.73 (2)
O2—O1—O3^xv	118.72 (2)	118.31 (2)	119.12 (2)
O2—O1—O3^vii	64.49 (2)	64.46 (2)	64.52 (2)
O2^xiv—O1—O2^v	82.64 (2)	82.17 (2)	83.13 (2)
O2^xiv—O1—O2^xvi	94.00 (2)	93.89 (2)	94.10 (2)
O2^xiv—O1—O3	129.27 (3)	129.12 (2)	129.42 (2)
O2^xiv—O1—O3^xvii	60.65 (2)	60.56 (2)	60.73 (2)
O2^xiv—O1—O3^xiv	55.937 (19)	55.829 (19)	56.049 (19)
O2^xiv—O1—O3^vi	112.42 (3)	112.30 (3)	112.54 (3)
O2^xiv—O1—O3^xv	64.49 (2)	64.46 (2)	64.52 (2)
O2^xiv—O1—O3^vii	118.71 (2)	118.31 (2)	119.12 (2)
O2^v—O1—O2^xvi	122.86 (3)	122.86 (3)	122.86 (3)
O2^v—O1—O3	144.22 (2)	143.79 (2)	144.63 (2)
O2^v—O1—O3^xvii	68.20 (2)	67.93 (2)	68.47 (2)
O2^v—O1—O3^xiv	76.162 (18)	76.030 (18)	76.290 (18)
O2^v—O1—O3^vi	61.16 (2)	61.16 (2)	61.16 (2)
O2^v—O1—O3^xv	147.13 (3)	146.63 (3)	147.64 (3)
O2^v—O1—O3^vii	63.292 (18)	63.167 (18)	63.416 (18)
O2^xvi—O1—O3	76.159 (18)	76.030 (18)	76.290 (18)
O2^xvi—O1—O3^xvii	61.16 (2)	61.16 (2)	61.16 (2)
O2^xvi—O1—O3^xiv	144.21 (2)	143.79 (2)	144.63 (2)
O2^xvi—O1—O3^vi	68.20 (2)	67.93 (2)	68.47 (2)
O2^xvi—O1—O3^xv	63.290 (18)	63.167 (18)	63.416 (18)
O2^xvi—O1—O3^vii	147.14 (3)	146.63 (3)	147.64 (3)
O3—O1—O3^xvii	137.24 (2)	137.10 (2)	137.39 (2)
O3—O1—O3^xiv	106.54 (3)	106.54 (3)	106.54 (3)
O3—O1—O3^vi	109.46 (2)	109.39 (2)	109.54 (2)
O3—O1—O3^xv	66.82 (2)	66.71 (2)	66.94 (2)
O3—O1—O3^vii	84.57 (2)	84.18 (2)	84.96 (2)
O3^xvii—O1—O3^xiv	109.46 (2)	109.39 (2)	109.54 (2)
O3^xvii—O1—O3^vi	53.62 (2)	53.62 (2)	53.62 (2)
O3^xvii—O1—O3^xv	94.34 (2)	94.30 (2)	94.37 (2)
O3^xvii—O1—O3^vii	130.77 (2)	130.60 (2)	130.95 (2)
O3^xiv—O1—O3^vi	137.25 (2)	137.10 (2)	137.39 (2)
O3^xiv—O1—O3^xv	84.56 (2)	84.18 (2)	84.96 (2)
O3^xiv—O1—O3^vii	66.82 (2)	66.71 (2)	66.94 (2)
O3^vi—O1—O3^xv	130.78 (2)	130.60 (2)	130.95 (2)
O3^vi—O1—O3^vii	94.34 (2)	94.30 (2)	94.37 (2)
O3^xv—O1—O3^vii	131.81 (3)	131.81 (3)	131.81 (3)
Sn—O2—Si^ii	138.89 (4)	138.62 (4)	139.17 (4)
Sn—O2—Si^iii	71.451 (16)	71.331 (15)	71.567 (16)
Sn—O2—Ca^ii	98.39 (2)	98.23 (2)	98.55 (2)
Sn—O2—Ca^xii	120.044 (19)	119.544 (18)	120.537 (19)
Sn—O2—O1	43.245 (16)	43.166 (16)	43.326 (16)
Sn—O2—O1^v	42.757 (14)	42.715 (13)	42.800 (14)
Sn—O2—O2^xviii	137.22 (3)	136.73 (3)	137.73 (3)
Sn—O2—O2^xix	126.38 (2)	126.31 (2)	126.46 (2)
Sn—O2—O2^xii	92.67 (2)	92.54 (2)	92.81 (2)
Sn—O2—O3	105.53 (3)	105.34 (3)	105.71 (3)
Sn—O2—O3^xviii	148.63 (3)	148.16 (3)	149.08 (3)
Sn—O2—O3^vi	45.503 (16)	45.391 (16)	45.616 (16)
Sn—O2—O3^xii	79.993 (18)	79.868 (18)	80.116 (18)
Sn—O2—O3^vii	44.822 (16)	44.781 (16)	44.864 (16)
Si^ii—O2—Si^iii	99.91 (3)	99.38 (3)	100.43 (3)
Si^ii—O2—Ca^ii	96.39 (3)	96.22 (3)	96.56 (3)
Si^ii—O2—Ca^xii	89.94 (3)	89.63 (3)	90.25 (3)
Si^ii—O2—O1	96.62 (3)	96.29 (3)	96.95 (3)
Si^ii—O2—O1^v	169.38 (4)	168.57 (4)	170.18 (4)
Si^ii—O2—O2^xviii	38.41 (3)	38.37 (3)	38.45 (3)
Si^ii—O2—O2^xix	94.64 (3)	94.46 (3)	94.82 (3)
Si^ii—O2—O2^xii	72.31 (3)	71.95 (3)	72.67 (3)
Si^ii—O2—O3	33.51 (2)	33.43 (2)	33.60 (2)
Si^ii—O2—O3^xviii	35.74 (2)	35.56 (2)	35.92 (2)
Si^ii—O2—O3^vi	133.90 (3)	133.17 (3)	134.65 (3)
Si^ii—O2—O3^xii	111.91 (3)	111.20 (3)	112.60 (3)
Si^ii—O2—O3^vii	111.78 (3)	111.41 (3)	112.15 (3)
Si^iii—O2—Ca^ii	163.30 (2)	162.89 (2)	163.72 (2)
Si^iii—O2—Ca^xii	66.801 (12)	66.426 (12)	67.170 (13)
Si^iii—O2—O1	82.841 (19)	82.816 (19)	82.867 (19)
Si^iii—O2—O1^v	70.141 (19)	69.991 (19)	70.288 (19)
Si^iii—O2—O2^xviii	138.21 (3)	137.73 (3)	138.68 (3)
Si^iii—O2—O2^xix	108.896 (19)	108.181 (19)	109.598 (19)
Si^iii—O2—O2^xii	27.594 (12)	27.423 (12)	27.763 (12)
Si^iii—O2—O3	85.75 (2)	85.47 (2)	86.02 (2)
Si^iii—O2—O3^xviii	79.52 (2)	79.04 (2)	79.99 (2)
Si^iii—O2—O3^vi	115.59 (2)	115.53 (2)	115.66 (2)
Si^iii—O2—O3^xii	28.579 (13)	28.491 (13)	28.666 (13)
Si^iii—O2—O3^vii	29.203 (14)	29.103 (14)	29.300 (14)
Ca^ii—O2—Ca^xii	109.80 (2)	109.07 (2)	110.54 (2)
Ca^ii—O2—O1	98.94 (2)	98.54 (2)	99.33 (2)
Ca^ii—O2—O1^v	93.35 (2)	92.85 (2)	93.86 (2)
Ca^ii—O2—O2^xviii	57.979 (18)	57.846 (18)	58.116 (18)
Ca^ii—O2—O2^xix	65.888 (18)	64.739 (18)	67.062 (18)
Ca^ii—O2—O2^xii	168.14 (2)	168.05 (2)	168.24 (2)
Ca^ii—O2—O3	110.11 (2)	109.90 (2)	110.33 (2)
Ca^ii—O2—O3^xviii	112.54 (2)	112.17 (2)	112.92 (2)
Ca^ii—O2—O3^vi	52.892 (17)	52.843 (17)	52.940 (17)
Ca^ii—O2—O3^xii	138.70 (3)	138.08 (3)	139.33 (3)
Ca^ii—O2—O3^vii	143.20 (3)	143.08 (3)	143.33 (3)
Ca^xii—O2—O1	149.62 (2)	149.26 (2)	149.98 (2)
Ca^xii—O2—O1^v	82.769 (17)	82.294 (17)	83.238 (18)
Ca^xii—O2—O2^xviii	102.17 (3)	102.07 (3)	102.28 (3)
Ca^xii—O2—O2^xix	43.910 (14)	43.482 (14)	44.330 (15)
Ca^xii—O2—O2^xii	67.576 (17)	67.156 (17)	67.991 (17)
Ca^xii—O2—O3	112.00 (2)	111.78 (2)	112.21 (2)
Ca^xii—O2—O3^xviii	54.877 (18)	54.712 (18)	55.038 (18)
Ca^xii—O2—O3^vi	129.83 (2)	129.63 (2)	130.02 (2)
Ca^xii—O2—O3^xii	44.197 (15)	43.817 (14)	44.573 (15)
Ca^xii—O2—O3^vii	93.952 (19)	93.470 (19)	94.427 (19)
O1—O2—O1^v	86.00 (2)	85.90 (2)	86.11 (2)
O1—O2—O2^xviii	101.27 (2)	101.10 (2)	101.45 (2)
O1—O2—O2^xix	162.06 (3)	161.52 (3)	162.61 (3)
O1—O2—O2^xii	86.20 (2)	86.02 (2)	86.37 (2)
O1—O2—O3	64.71 (2)	64.53 (2)	64.90 (2)
O1—O2—O3^xviii	122.50 (3)	122.39 (3)	122.60 (3)
O1—O2—O3^vi	62.06 (2)	62.02 (2)	62.09 (2)
O1—O2—O3^xii	106.61 (2)	106.57 (2)	106.65 (2)
O1—O2—O3^vii	56.075 (19)	55.991 (19)	56.161 (19)
O1^v—O2—O2^xviii	151.05 (3)	150.51 (3)	151.60 (3)
O1^v—O2—O2^xix	85.46 (2)	85.27 (2)	85.66 (2)
O1^v—O2—O2^xii	97.68 (2)	97.35 (2)	98.00 (2)
O1^v—O2—O3	144.39 (3)	144.27 (3)	144.51 (3)
O1^v—O2—O3^xviii	135.30 (3)	134.65 (3)	135.95 (3)
O1^v—O2—O3^vi	56.210 (18)	56.113 (18)	56.310 (18)
O1^v—O2—O3^xii	57.571 (18)	57.441 (18)	57.698 (18)
O1^v—O2—O3^vii	61.332 (19)	61.312 (19)	61.352 (19)
O2^xviii—O2—O2^xix	79.27 (2)	78.88 (2)	79.66 (2)
O2^xviii—O2—O2^xii	110.65 (2)	110.33 (2)	110.95 (2)
O2^xviii—O2—O3	60.24 (2)	60.14 (2)	60.34 (2)
O2^xviii—O2—O3^xviii	63.07 (2)	63.05 (2)	63.09 (2)
O2^xviii—O2—O3^vi	102.38 (2)	101.81 (2)	102.96 (2)
O2^xviii—O2—O3^xii	141.99 (3)	141.51 (3)	142.45 (3)
O2^xviii—O2—O3^vii	144.80 (3)	144.55 (3)	145.04 (3)
O2^xix—O2—O2^xii	110.57 (2)	109.73 (2)	111.39 (2)
O2^xix—O2—O3	128.09 (3)	127.95 (3)	128.21 (3)
O2^xix—O2—O3^xviii	74.00 (2)	73.63 (2)	74.36 (2)
O2^xix—O2—O3^vi	100.17 (2)	99.72 (2)	100.63 (2)
O2^xix—O2—O3^xii	81.85 (2)	81.24 (2)	82.44 (2)
O2^xix—O2—O3^vii	131.08 (2)	130.43 (2)	131.71 (2)
O2^xii—O2—O3	62.372 (18)	62.243 (18)	62.499 (18)
O2^xii—O2—O3^xviii	56.109 (19)	55.749 (19)	56.464 (19)
O2^xii—O2—O3^vi	138.06 (2)	137.97 (2)	138.15 (2)
O2^xii—O2—O3^xii	47.632 (15)	47.314 (15)	47.945 (15)
O2^xii—O2—O3^vii	47.953 (17)	47.794 (17)	48.108 (17)
O3—O2—O3^xviii	59.75 (2)	59.73 (2)	59.78 (2)
O3—O2—O3^vi	118.17 (3)	117.79 (3)	118.56 (3)
O3—O2—O3^xii	110.00 (2)	109.60 (2)	110.40 (2)
O3—O2—O3^vii	84.76 (2)	84.54 (2)	84.97 (2)
O3^xviii—O2—O3^vi	164.87 (2)	164.35 (2)	165.41 (2)
O3^xviii—O2—O3^xii	80.13 (2)	79.59 (2)	80.67 (2)
O3^xviii—O2—O3^vii	104.06 (2)	103.55 (2)	104.56 (2)
O3^vi—O2—O3^xii	113.28 (2)	113.240 (19)	113.32 (2)
O3^vi—O2—O3^vii	90.33 (2)	90.24 (2)	90.42 (2)
O3^xii—O2—O3^vii	50.639 (19)	50.516 (19)	50.758 (19)
Sn^x—O3—Si^ii	126.58 (4)	126.30 (4)	126.86 (4)
Sn^x—O3—Ca	97.59 (2)	97.48 (2)	97.70 (2)
Sn^x—O3—Ca^xv	91.466 (18)	91.240 (18)	91.698 (18)
Sn^x—O3—O1	141.10 (3)	140.86 (3)	141.34 (3)
Sn^x—O3—O1^ix	40.560 (13)	40.510 (13)	40.610 (13)
Sn^x—O3—O1^xv	45.102 (17)	45.066 (17)	45.139 (17)
Sn^x—O3—O2	153.30 (3)	153.05 (3)	153.56 (3)
Sn^x—O3—O2^xviii	120.29 (3)	119.83 (3)	120.75 (3)
Sn^x—O3—O2^x	45.173 (16)	45.141 (16)	45.206 (16)
Sn^x—O3—O2^xii	91.06 (2)	90.99 (2)	91.13 (2)
Sn^x—O3—O2^xxii	44.500 (16)	44.425 (16)	44.576 (16)
Sn^x—O3—O3^xviii	95.57 (3)	95.38 (3)	95.75 (3)
Sn^x—O3—O3^xv	97.12 (2)	96.88 (2)	97.37 (2)
Si^ii—O3—Ca	123.38 (3)	122.68 (2)	124.09 (3)
Si^ii—O3—Ca^xv	107.03 (3)	106.42 (3)	107.63 (3)
Si^ii—O3—O1	91.20 (3)	91.12 (3)	91.29 (3)
Si^ii—O3—O1^ix	98.20 (4)	98.13 (4)	98.27 (4)
Si^ii—O3—O1^xv	139.34 (3)	138.95 (3)	139.72 (3)
Si^ii—O3—O2	33.37 (2)	33.32 (2)	33.42 (2)
Si^ii—O3—O2^xviii	35.58 (2)	35.36 (2)	35.80 (2)
Si^ii—O3—O2^x	151.02 (4)	150.84 (4)	151.21 (4)
Si^ii—O3—O2^xii	78.57 (3)	78.51 (3)	78.63 (3)
Si^ii—O3—O2^xxii	88.61 (3)	88.18 (3)	89.03 (3)
Si^ii—O3—O3^xviii	35.01 (3)	34.99 (3)	35.03 (3)
Si^ii—O3—O3^xv	132.64 (4)	132.44 (4)	132.83 (4)
Ca—O3—Ca^xv	104.88 (2)	104.34 (2)	105.41 (2)
Ca—O3—O1	47.116 (18)	47.042 (18)	47.184 (18)
Ca—O3—O1^ix	94.88 (2)	94.44 (2)	95.33 (2)
Ca—O3—O1^xv	96.31 (2)	95.88 (2)	96.73 (2)
Ca—O3—O2	91.65 (2)	91.02 (2)	92.27 (2)
Ca—O3—O2^xviii	141.86 (3)	141.56 (3)	142.15 (3)
Ca—O3—O2^x	52.425 (18)	52.349 (18)	52.501 (18)
Ca—O3—O2^xii	65.760 (17)	64.772 (17)	66.760 (17)
Ca—O3—O2^xxii	142.08 (3)	141.90 (3)	142.28 (3)
Ca—O3—O3^xviii	123.06 (2)	122.25 (2)	123.88 (2)
Ca—O3—O3^xv	56.760 (17)	56.179 (17)	57.337 (18)
Ca^xv—O3—O1	84.70 (2)	84.64 (2)	84.76 (2)
Ca^xv—O3—O1^ix	130.58 (2)	130.46 (2)	130.71 (2)
Ca^xv—O3—O1^xv	47.976 (18)	47.726 (18)	48.235 (18)
Ca^xv—O3—O2	110.33 (2)	109.60 (2)	111.04 (2)
Ca^xv—O3—O2^xviii	72.272 (19)	71.458 (19)	73.065 (18)
Ca^xv—O3—O2^x	101.24 (2)	100.87 (2)	101.63 (2)
Ca^xv—O3—O2^xii	170.55 (3)	169.96 (3)	171.16 (3)
Ca^xv—O3—O2^xxii	80.991 (17)	80.891 (17)	81.087 (17)
Ca^xv—O3—O3^xviii	129.88 (2)	129.34 (2)	130.40 (2)
Ca^xv—O3—O3^xv	48.117 (14)	47.905 (14)	48.337 (14)
O1—O3—O1^ix	137.24 (2)	137.08 (2)	137.41 (2)
O1—O3—O1^xv	113.18 (3)	113.02 (3)	113.33 (3)
O1—O3—O2	59.35 (2)	59.26 (2)	59.43 (2)
O1—O3—O2^xviii	95.35 (2)	95.20 (2)	95.49 (2)
O1—O3—O2^x	97.65 (2)	97.43 (2)	97.87 (2)
O1—O3—O2^xii	87.625 (18)	87.307 (18)	87.947 (18)
O1—O3—O2^xxii	164.96 (2)	164.84 (2)	165.09 (2)
O1—O3—O3^xviii	116.40 (2)	116.34 (2)	116.46 (2)
O1—O3—O3^xv	52.827 (17)	52.766 (16)	52.888 (17)
O1^ix—O3—O1^xv	85.66 (2)	85.61 (2)	85.71 (2)
O1^ix—O3—O2	113.91 (3)	113.58 (3)	114.24 (3)
O1^ix—O3—O2^xviii	116.15 (3)	116.04 (3)	116.26 (3)
O1^ix—O3—O2^x	57.297 (19)	57.219 (19)	57.375 (19)
O1^ix—O3—O2^xii	54.230 (15)	54.085 (15)	54.375 (15)
O1^ix—O3—O2^xxii	57.505 (17)	57.487 (17)	57.524 (17)
O1^ix—O3—O3^xviii	63.19 (2)	63.13 (2)	63.24 (2)
O1^ix—O3—O3^xv	128.94 (3)	128.71 (3)	129.18 (3)
O1^xv—O3—O2	158.20 (3)	157.72 (3)	158.67 (3)
O1^xv—O3—O2^xviii	107.06 (2)	106.47 (2)	107.64 (2)
O1^xv—O3—O2^x	60.497 (19)	60.441 (19)	60.55 (2)
O1^xv—O3—O2^xii	131.70 (3)	131.59 (3)	131.81 (3)
O1^xv—O3—O2^xxii	59.435 (19)	59.373 (19)	59.498 (19)
O1^xv—O3—O3^xviii	129.80 (3)	129.56 (3)	130.04 (3)
O1^xv—O3—O3^xv	60.350 (19)	60.176 (19)	60.525 (19)
O2—O3—O2^xviii	56.685 (19)	56.585 (19)	56.788 (19)
O2—O3—O2^x	137.63 (2)	137.15 (2)	138.12 (2)
O2—O3—O2^xii	69.996 (19)	69.606 (19)	70.396 (19)
O2—O3—O2^xxii	121.97 (3)	121.58 (3)	122.35 (3)
O2—O3—O3^xviii	58.79 (2)	58.62 (2)	58.97 (2)
O2—O3—O3^xv	108.83 (3)	108.55 (3)	109.11 (3)
O2^xviii—O3—O2^x	164.88 (2)	164.36 (2)	165.39 (2)
O2^xviii—O3—O2^xii	114.02 (3)	113.79 (3)	114.26 (3)
O2^xviii—O3—O2^xxii	75.95 (2)	75.44 (2)	76.45 (2)
O2^xviii—O3—O3^xviii	61.45 (2)	61.30 (2)	61.61 (2)
O2^xviii—O3—O3^xv	110.02 (2)	109.65 (2)	110.39 (2)
O2^x—O3—O2^xii	74.322 (19)	74.099 (19)	74.547 (19)
O2^x—O3—O2^xxii	89.67 (2)	89.57 (2)	89.78 (2)
O2^x—O3—O3^xviii	118.40 (3)	118.29 (3)	118.52 (3)
O2^x—O3—O3^xv	72.48 (2)	72.27 (2)	72.69 (2)
O2^xii—O3—O2^xxii	107.05 (2)	106.73 (2)	107.36 (2)
O2^xii—O3—O3^xviii	58.835 (19)	58.651 (19)	59.018 (19)
O2^xii—O3—O3^xv	122.51 (2)	122.07 (2)	122.95 (2)
O2^xxii—O3—O3^xviii	70.53 (2)	70.22 (2)	70.83 (2)
O2^xxii—O3—O3^xv	118.18 (2)	117.99 (2)	118.36 (2)
O3^xviii—O3—O3^xv	167.19 (3)	167.04 (3)	167.34 (3)

Symmetry codes: (i) x₁, x₂−1, x₃, x₄; (ii) x₁+1/2, x₂−1/2, x₃, x₄; (iii) −x₁, −x₂+1, −x₃, −x₄; (iv) −x₁−1/2, −x₂+1/2, −x₃, −x₄; (v) −x₁, −x₂, −x₃, −x₄; (vi) −x₁+1/2, x₂−1/2, −x₃+1/2, x₄+1/2; (vii) x₁−1/2, −x₂+1/2, x₃−1/2, −x₄+1/2; (viii) x₁−1/2, x₂+1/2, x₃, x₄; (ix) x₁+1/2, x₂+1/2, x₃, x₄; (x) −x₁+1/2, x₂+1/2, −x₃+1/2, x₄+1/2; (xi) x₁, −x₂+1, x₃+1/2, −x₄+1/2; (xii) −x₁+1/2, −x₂+1/2, −x₃, −x₄; (xiii) x₁−1/2, −x₂+1/2, x₃+1/2, −x₄+1/2; (xiv) −x₁, x₂, −x₃+1/2, x₄+1/2; (xv) −x₁+1/2, −x₂+1/2, −x₃+1, −x₄; (xvi) x₁, −x₂, x₃+1/2, −x₄+1/2; (xvii) x₁−1/2, x₂−1/2, x₃, x₄; (xviii) −x₁+1, x₂, −x₃+1/2, x₄+1/2; (xix) −x₁+1, −x₂, −x₃, −x₄; (xx) x₁, x₂+1, x₃, x₄; (xxi) −x₁, x₂+1, −x₃+1/2, x₄+1/2; (xxii) x₁+1/2, −x₂+1/2, x₃+1/2, −x₄+1/2.

(II)

Crystal data

CaO5SiSn	F(000) = 496
Mr = 266.9	Dx = 4.552 Mg m^−3
Monoclinic, C2/c	Synchrotron radiation, λ = 0.61992 Å
Hall symbol: -C 2yc	Cell parameters from 11467 reflections
a = 6.6667 (2) Å	θ = 3.7–51°
b = 8.8934 (3) Å	µ = 5.52 mm^−1
c = 7.1520 (3) Å	T = 298 K
β = 113.323 (3)°	Irregular, yellow
V = 389.39 (3) Å^3	0.16 × 0.09 × 0.09 mm
Z = 4

Data collection

Esperanto-CrysAlisPro-abstract goniometer imported esperanto images diffractometer	2748 independent reflections
Radiation source: synchrotron	2651 reflections with I > 3σ(I)
Synchrotron monochromator	Rint = 0.019
ω and φ scans	θmax = 50.9°, θmin = 3.7°
Absorption correction: multi-scan CrysAlisPro 1.171.38.46 (Rigaku Oxford Diffraction, 2015) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	h = −16→13
Tmin = 0.754, Tmax = 1	k = −19→21
11739 measured reflections	l = −16→17

Refinement

Refinement on F^2	0 constraints
R[F^2 > 2σ(F^2)] = 0.026	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.01I^2)
wR(F^2) = 0.113	(Δ/σ)max = 0.001
S = 1.06	Δρmax = 0.70 e Å^−3
2748 reflections	Δρmin = −0.67 e Å^−3
41 parameters	Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 5800 (900)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn	0	0	0	0.00385 (4)
Si	0	0.68145 (5)	0.25	0.00444 (6)
Ca	0	0.33729 (4)	0.25	0.01704 (7)
O1	0	0.08665 (6)	0.25	0.00729 (10)
O2	0.32452 (6)	0.06780 (5)	0.08695 (6)	0.00756 (7)
O3	0.39029 (6)	0.28799 (4)	0.37214 (5)	0.00670 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn	0.00400 (5)	0.00386 (5)	0.00362 (5)	−0.000007 (5)	0.00145 (4)	−0.000202 (5)
Si	0.00380 (8)	0.00502 (13)	0.00446 (8)	0	0.00157 (6)	0
Ca	0.00667 (7)	0.00372 (8)	0.03245 (15)	0	−0.00108 (7)	0
O1	0.01245 (16)	0.00528 (15)	0.00510 (12)	0	0.00450 (11)	0
O2	0.00522 (10)	0.00704 (11)	0.00912 (11)	−0.00141 (7)	0.00147 (7)	−0.00274 (8)
O3	0.00687 (10)	0.00537 (13)	0.00879 (11)	−0.00077 (7)	0.00408 (8)	−0.00228 (7)

Geometric parameters (Å, º)

Sn—Si^i	3.3500 (4)	Ca—O2^xii	3.1813 (5)
Sn—Si^ii	3.4918 (3)	Ca—O2^xiii	3.1813 (5)
Sn—Si^iii	3.3500 (4)	Ca—O3	2.4343 (4)
Sn—Si^iv	3.4918 (3)	Ca—O3^xiv	2.4343 (4)
Sn—Ca	3.4921 (4)	Ca—O3^xv	2.7413 (5)
Sn—Ca^ii	3.4180 (3)	Ca—O3^vii	2.7413 (5)
Sn—Ca^v	3.4921 (4)	O1—O2	2.8402 (5)
Sn—Ca^iv	3.4180 (3)	O1—O2^xiv	2.8402 (5)
Sn—O1	1.9470 (3)	O1—O2^v	2.8717 (5)
Sn—O1^v	1.9470 (3)	O1—O2^xvi	2.8717 (5)
Sn—O2	2.0894 (4)	O1—O3	2.9900 (5)
Sn—O2^v	2.0894 (4)	O1—O3^xvii	2.9763 (7)
Sn—O3^vi	2.0968 (4)	O1—O3^xiv	2.9900 (5)
Sn—O3^vii	2.0968 (4)	O1—O3^vi	2.9763 (7)
Si—Ca	3.0608 (6)	O1—O3^xv	2.7416 (5)
Si—O1^viii	3.4383 (3)	O1—O3^vii	2.7416 (5)
Si—O1^ix	3.4383 (3)	O2—O2^xviii	2.5677 (5)
Si—O2^viii	1.6339 (5)	O2—O2^xix	3.2832 (7)
Si—O2^x	1.6339 (5)	O2—O2^xii	3.4724 (6)
Si—O2^iii	3.3663 (5)	O2—O3	2.7348 (6)
Si—O2^xi	3.3663 (5)	O2—O3^xviii	2.6635 (6)
Si—O3^viii	1.6437 (5)	O2—O3^vi	2.9430 (6)
Si—O3^x	1.6437 (5)	O2—O3^xii	3.2792 (6)
Ca—O1	2.2291 (7)	O2—O3^vii	2.9772 (5)
Ca—O2^viii	2.4189 (5)	O3—O3^xviii	2.6862 (7)
Ca—O2^x	2.4189 (5)	O3—O3^xv	3.1638 (7)
Si^i—Sn—Si^ii	108.617 (7)	Sn^xiv—O1—O3	106.567 (10)
Si^i—Sn—Si^iii	180.0 (5)	Sn^xiv—O1—O3^xvii	44.596 (13)
Si^i—Sn—Si^iv	71.383 (7)	Sn^xiv—O1—O3^xiv	100.890 (10)
Si^i—Sn—Ca	116.944 (6)	Sn^xiv—O1—O3^vi	90.33 (2)
Si^i—Sn—Ca^ii	64.460 (5)	Sn^xiv—O1—O3^xv	49.662 (10)
Si^i—Sn—Ca^v	63.056 (6)	Sn^xiv—O1—O3^vii	165.744 (9)
Si^i—Sn—Ca^iv	115.540 (5)	Si^xvii—O1—Si^ii	151.61 (2)
Si^i—Sn—O1	81.057 (16)	Si^xvii—O1—Ca	75.805 (12)
Si^i—Sn—O1^v	98.943 (16)	Si^xvii—O1—O2	155.583 (12)
Si^i—Sn—O2	107.699 (12)	Si^xvii—O1—O2^xiv	28.161 (9)
Si^i—Sn—O2^v	72.301 (12)	Si^xvii—O1—O2^v	73.082 (10)
Si^i—Sn—O3^vi	23.148 (12)	Si^xvii—O1—O2^xvi	121.708 (11)
Si^i—Sn—O3^vii	156.852 (12)	Si^xvii—O1—O3	125.78 (2)
Si^ii—Sn—Si^iii	71.383 (7)	Si^xvii—O1—O3^xvii	82.412 (12)
Si^ii—Sn—Si^iv	180.0 (5)	Si^xvii—O1—O3^xiv	28.552 (11)
Si^ii—Sn—Ca	62.249 (6)	Si^xvii—O1—O3^vi	124.730 (16)
Si^ii—Sn—Ca^ii	52.573 (9)	Si^xvii—O1—O3^xv	77.323 (11)
Si^ii—Sn—Ca^v	117.751 (6)	Si^xvii—O1—O3^vii	91.146 (12)
Si^ii—Sn—Ca^iv	127.427 (9)	Si^ii—O1—Ca	75.805 (12)
Si^ii—Sn—O1	72.178 (7)	Si^ii—O1—O2	28.161 (9)
Si^ii—Sn—O1^v	107.822 (7)	Si^ii—O1—O2^xiv	155.583 (12)
Si^ii—Sn—O2	17.858 (13)	Si^ii—O1—O2^v	121.708 (11)
Si^ii—Sn—O2^v	162.142 (13)	Si^ii—O1—O2^xvi	73.082 (10)
Si^ii—Sn—O3^vi	95.441 (12)	Si^ii—O1—O3	28.552 (11)
Si^ii—Sn—O3^vii	84.559 (12)	Si^ii—O1—O3^xvii	124.730 (16)
Si^iii—Sn—Si^iv	108.617 (7)	Si^ii—O1—O3^xiv	125.78 (2)
Si^iii—Sn—Ca	63.056 (6)	Si^ii—O1—O3^vi	82.412 (12)
Si^iii—Sn—Ca^ii	115.540 (5)	Si^ii—O1—O3^xv	91.146 (12)
Si^iii—Sn—Ca^v	116.944 (6)	Si^ii—O1—O3^vii	77.323 (11)
Si^iii—Sn—Ca^iv	64.460 (5)	Ca—O1—O2	93.382 (15)
Si^iii—Sn—O1	98.943 (16)	Ca—O1—O2^xiv	93.382 (15)
Si^iii—Sn—O1^v	81.057 (16)	Ca—O1—O2^v	118.576 (13)
Si^iii—Sn—O2	72.301 (12)	Ca—O1—O2^xvi	118.576 (13)
Si^iii—Sn—O2^v	107.699 (12)	Ca—O1—O3	53.210 (11)
Si^iii—Sn—O3^vi	156.852 (12)	Ca—O1—O3^xvii	153.176 (10)
Si^iii—Sn—O3^vii	23.148 (12)	Ca—O1—O3^xiv	53.210 (11)
Si^iv—Sn—Ca	117.751 (6)	Ca—O1—O3^vi	153.176 (10)
Si^iv—Sn—Ca^ii	127.427 (9)	Ca—O1—O3^xv	66.004 (14)
Si^iv—Sn—Ca^v	62.249 (6)	Ca—O1—O3^vii	66.004 (14)
Si^iv—Sn—Ca^iv	52.573 (9)	O2—O1—O2^xiv	173.24 (3)
Si^iv—Sn—O1	107.822 (7)	O2—O1—O2^v	94.043 (14)
Si^iv—Sn—O1^v	72.178 (7)	O2—O1—O2^xvi	82.707 (13)
Si^iv—Sn—O2	162.142 (13)	O2—O1—O3	55.877 (12)
Si^iv—Sn—O2^v	17.858 (13)	O2—O1—O3^xvii	112.55 (2)
Si^iv—Sn—O3^vi	84.559 (12)	O2—O1—O3^xiv	129.171 (17)
Si^iv—Sn—O3^vii	95.441 (12)	O2—O1—O3^vi	60.738 (14)
Ca—Sn—Ca^ii	107.068 (6)	O2—O1—O3^xv	118.649 (13)
Ca—Sn—Ca^v	180.0 (5)	O2—O1—O3^vii	64.440 (12)
Ca—Sn—Ca^iv	72.932 (6)	O2^xiv—O1—O2^v	82.707 (13)
Ca—Sn—O1	35.887 (16)	O2^xiv—O1—O2^xvi	94.043 (14)
Ca—Sn—O1^v	144.113 (16)	O2^xiv—O1—O3	129.171 (17)
Ca—Sn—O2	79.025 (13)	O2^xiv—O1—O3^xvii	60.738 (14)
Ca—Sn—O2^v	100.975 (13)	O2^xiv—O1—O3^xiv	55.877 (12)
Ca—Sn—O3^vi	128.303 (11)	O2^xiv—O1—O3^vi	112.55 (2)
Ca—Sn—O3^vii	51.697 (11)	O2^xiv—O1—O3^xv	64.440 (12)
Ca^ii—Sn—Ca^v	72.932 (6)	O2^xiv—O1—O3^vii	118.649 (13)
Ca^ii—Sn—Ca^iv	180.0 (5)	O2^v—O1—O2^xvi	122.85 (2)
Ca^ii—Sn—O1	92.393 (8)	O2^v—O1—O3	144.193 (13)
Ca^ii—Sn—O1^v	87.607 (8)	O2^v—O1—O3^xvii	68.186 (15)
Ca^ii—Sn—O2	44.444 (13)	O2^v—O1—O3^xiv	76.228 (11)
Ca^ii—Sn—O2^v	135.556 (13)	O2^v—O1—O3^vi	61.176 (14)
Ca^ii—Sn—O3^vi	44.898 (12)	O2^v—O1—O3^xv	147.146 (13)
Ca^ii—Sn—O3^vii	135.102 (12)	O2^v—O1—O3^vii	63.191 (12)
Ca^v—Sn—Ca^iv	107.068 (6)	O2^xvi—O1—O3	76.228 (11)
Ca^v—Sn—O1	144.113 (16)	O2^xvi—O1—O3^xvii	61.176 (14)
Ca^v—Sn—O1^v	35.887 (16)	O2^xvi—O1—O3^xiv	144.193 (13)
Ca^v—Sn—O2	100.975 (13)	O2^xvi—O1—O3^vi	68.186 (15)
Ca^v—Sn—O2^v	79.025 (13)	O2^xvi—O1—O3^xv	63.191 (12)
Ca^v—Sn—O3^vi	51.697 (11)	O2^xvi—O1—O3^vii	147.146 (13)
Ca^v—Sn—O3^vii	128.303 (11)	O3—O1—O3^xvii	137.327 (12)
Ca^iv—Sn—O1	87.607 (8)	O3—O1—O3^xiv	106.42 (2)
Ca^iv—Sn—O1^v	92.393 (8)	O3—O1—O3^vi	109.490 (12)
Ca^iv—Sn—O2	135.556 (13)	O3—O1—O3^xv	66.846 (14)
Ca^iv—Sn—O2^v	44.444 (13)	O3—O1—O3^vii	84.613 (15)
Ca^iv—Sn—O3^vi	135.102 (12)	O3^xvii—O1—O3^xiv	109.490 (12)
Ca^iv—Sn—O3^vii	44.898 (12)	O3^xvii—O1—O3^vi	53.648 (16)
O1—Sn—O1^v	180.0 (5)	O3^xvii—O1—O3^xv	94.258 (13)
O1—Sn—O2	89.367 (13)	O3^xvii—O1—O3^vii	130.660 (16)
O1—Sn—O2^v	90.633 (13)	O3^xiv—O1—O3^vi	137.327 (12)
O1—Sn—O3^vi	94.716 (18)	O3^xiv—O1—O3^xv	84.613 (15)
O1—Sn—O3^vii	85.284 (18)	O3^xiv—O1—O3^vii	66.846 (14)
O1^v—Sn—O2	90.633 (13)	O3^vi—O1—O3^xv	130.660 (16)
O1^v—Sn—O2^v	89.367 (13)	O3^vi—O1—O3^vii	94.258 (13)
O1^v—Sn—O3^vi	85.284 (18)	O3^xv—O1—O3^vii	132.01 (2)
O1^v—Sn—O3^vii	94.716 (18)	Sn—O2—Si^ii	139.05 (3)
O2—Sn—O2^v	180.0 (5)	Sn—O2—Si^iii	71.449 (11)
O2—Sn—O3^vi	89.338 (16)	Sn—O2—Ca^ii	98.339 (18)
O2—Sn—O3^vii	90.662 (16)	Sn—O2—Ca^xii	119.941 (15)
O2^v—Sn—O3^vi	90.662 (16)	Sn—O2—O1	43.273 (11)
O2^v—Sn—O3^vii	89.338 (16)	Sn—O2—O1^v	42.684 (7)
O3^vi—Sn—O3^vii	180.0 (5)	Sn—O2—O2^xviii	137.23 (2)
Sn^xx—Si—Sn^viii	108.617 (5)	Sn—O2—O2^xix	126.189 (18)
Sn^xx—Si—Sn^xxi	64.516 (9)	Sn—O2—O2^xii	92.694 (14)
Sn^xx—Si—Sn^x	117.542 (5)	Sn—O2—O3	105.66 (2)
Sn^xx—Si—Ca	147.742 (5)	Sn—O2—O3^xviii	148.74 (2)
Sn^xx—Si—O1^viii	114.345 (11)	Sn—O2—O3^vi	45.433 (11)
Sn^xx—Si—O1^ix	90.144 (9)	Sn—O2—O3^xii	79.898 (12)
Sn^xx—Si—O2^viii	107.066 (17)	Sn—O2—O3^vii	44.769 (11)
Sn^xx—Si—O2^x	138.828 (18)	Si^ii—O2—Si^iii	100.18 (2)
Sn^xx—Si—O2^iii	36.250 (8)	Si^ii—O2—Ca^ii	96.16 (2)
Sn^xx—Si—O2^xi	71.705 (12)	Si^ii—O2—Ca^xii	90.139 (19)
Sn^xx—Si—O3^viii	83.70 (2)	Si^ii—O2—O1	96.72 (2)
Sn^xx—Si—O3^x	30.099 (16)	Si^ii—O2—O1^v	169.56 (3)
Sn^viii—Si—Sn^xxi	117.542 (5)	Si^ii—O2—O2^xviii	38.212 (18)
Sn^viii—Si—Sn^x	124.949 (14)	Si^ii—O2—O2^xix	94.666 (19)
Sn^viii—Si—Ca	62.474 (7)	Si^ii—O2—O2^xii	72.59 (2)
Sn^viii—Si—O1^viii	32.621 (5)	Si^ii—O2—O3	33.560 (14)
Sn^viii—Si—O1^ix	127.995 (14)	Si^ii—O2—O3^xviii	35.767 (14)
Sn^viii—Si—O2^viii	23.088 (16)	Si^ii—O2—O3^vi	133.72 (2)
Sn^viii—Si—O2^x	110.37 (2)	Si^ii—O2—O3^xii	112.22 (2)
Sn^viii—Si—O2^iii	74.152 (7)	Si^ii—O2—O3^vii	112.15 (2)
Sn^viii—Si—O2^xi	152.296 (10)	Si^iii—O2—Ca^ii	163.259 (17)
Sn^viii—Si—O3^viii	90.178 (13)	Si^iii—O2—Ca^xii	66.849 (10)
Sn^viii—Si—O3^x	121.985 (11)	Si^iii—O2—O1	82.917 (12)
Sn^xxi—Si—Sn^x	108.617 (5)	Si^iii—O2—O1^v	70.061 (14)
Sn^xxi—Si—Ca	147.742 (5)	Si^iii—O2—O2^xviii	138.29 (2)
Sn^xxi—Si—O1^viii	90.144 (9)	Si^iii—O2—O2^xix	108.939 (15)
Sn^xxi—Si—O1^ix	114.345 (11)	Si^iii—O2—O2^xii	27.590 (9)
Sn^xxi—Si—O2^viii	138.828 (18)	Si^iii—O2—O3	85.838 (15)
Sn^xxi—Si—O2^x	107.066 (17)	Si^iii—O2—O3^xviii	79.638 (14)
Sn^xxi—Si—O2^iii	71.705 (12)	Si^iii—O2—O3^vi	115.542 (13)
Sn^xxi—Si—O2^xi	36.250 (8)	Si^iii—O2—O3^xii	28.601 (9)
Sn^xxi—Si—O3^viii	30.099 (16)	Si^iii—O2—O3^vii	29.217 (10)
Sn^xxi—Si—O3^x	83.70 (2)	Ca^ii—O2—Ca^xii	109.716 (16)
Sn^x—Si—Ca	62.474 (7)	Ca^ii—O2—O1	98.840 (18)
Sn^x—Si—O1^viii	127.995 (14)	Ca^ii—O2—O1^v	93.385 (18)
Sn^x—Si—O1^ix	32.621 (5)	Ca^ii—O2—O2^xviii	57.944 (13)
Sn^x—Si—O2^viii	110.37 (2)	Ca^ii—O2—O2^xix	65.804 (13)
Sn^x—Si—O2^x	23.088 (16)	Ca^ii—O2—O2^xii	168.191 (15)
Sn^x—Si—O2^iii	152.296 (10)	Ca^ii—O2—O3	110.070 (16)
Sn^x—Si—O2^xi	74.152 (7)	Ca^ii—O2—O3^xviii	112.470 (15)
Sn^x—Si—O3^viii	121.985 (11)	Ca^ii—O2—O3^vi	52.909 (12)
Sn^x—Si—O3^x	90.178 (13)	Ca^ii—O2—O3^xii	138.618 (19)
Ca—Si—O1^viii	75.805 (12)	Ca^ii—O2—O3^vii	143.103 (19)
Ca—Si—O1^ix	75.805 (12)	Ca^xii—O2—O1	149.738 (16)
Ca—Si—O2^viii	51.788 (19)	Ca^xii—O2—O1^v	82.649 (12)
Ca—Si—O2^x	51.788 (19)	Ca^xii—O2—O2^xviii	102.237 (17)
Ca—Si—O2^iii	131.485 (9)	Ca^xii—O2—O2^xix	43.912 (11)
Ca—Si—O2^xi	131.485 (9)	Ca^xii—O2—O2^xii	67.666 (13)
Ca—Si—O3^viii	125.20 (2)	Ca^xii—O2—O3	112.120 (18)
Ca—Si—O3^x	125.20 (2)	Ca^xii—O2—O3^xviii	55.082 (13)
O1^viii—Si—O1^ix	151.61 (2)	Ca^xii—O2—O3^vi	129.719 (18)
O1^viii—Si—O2^viii	55.121 (17)	Ca^xii—O2—O3^xii	44.239 (10)
O1^viii—Si—O2^x	105.57 (2)	Ca^xii—O2—O3^vii	93.949 (14)
O1^viii—Si—O2^iii	79.289 (11)	O1—O2—O1^v	85.957 (12)
O1^viii—Si—O2^xi	120.713 (12)	O1—O2—O2^xviii	101.264 (18)
O1^viii—Si—O3^viii	60.395 (16)	O1—O2—O2^xix	161.83 (2)
O1^viii—Si—O3^x	140.962 (17)	O1—O2—O2^xii	86.303 (17)
O1^ix—Si—O2^viii	105.57 (2)	O1—O2—O3	64.835 (16)
O1^ix—Si—O2^x	55.121 (17)	O1—O2—O3^xviii	122.56 (2)
O1^ix—Si—O2^iii	120.713 (12)	O1—O2—O3^vi	61.919 (17)
O1^ix—Si—O2^xi	79.289 (11)	O1—O2—O3^xii	106.639 (14)
O1^ix—Si—O3^viii	140.962 (17)	O1—O2—O3^vii	56.174 (13)
O1^ix—Si—O3^x	60.395 (16)	O1^v—O2—O2^xviii	151.05 (2)
O2^viii—Si—O2^x	103.58 (3)	O1^v—O2—O2^xix	85.384 (14)
O2^viii—Si—O2^iii	79.818 (17)	O1^v—O2—O2^xii	97.595 (15)
O2^viii—Si—O2^xi	175.06 (2)	O1^v—O2—O3	144.434 (18)
O2^viii—Si—O3^viii	113.10 (2)	O1^v—O2—O3^xviii	135.37 (2)
O2^viii—Si—O3^x	108.71 (2)	O1^v—O2—O3^vi	56.246 (13)
O2^x—Si—O2^iii	175.06 (2)	O1^v—O2—O3^xii	57.422 (13)
O2^x—Si—O2^xi	79.818 (17)	O1^v—O2—O3^vii	61.146 (13)
O2^x—Si—O3^viii	108.71 (2)	O2^xviii—O2—O2^xix	79.301 (16)
O2^x—Si—O3^x	113.10 (2)	O2^xviii—O2—O2^xii	110.730 (18)
O2^iii—Si—O2^xi	97.030 (16)	O2^xviii—O2—O3	60.209 (15)
O2^iii—Si—O3^viii	72.753 (19)	O2^xviii—O2—O3^xviii	63.007 (15)
O2^iii—Si—O3^x	62.147 (17)	O2^xviii—O2—O3^vi	102.355 (18)
O2^xi—Si—O3^viii	62.147 (17)	O2^xviii—O2—O3^xii	142.11 (2)
O2^xi—Si—O3^x	72.753 (19)	O2^xviii—O2—O3^vii	144.97 (2)
O3^viii—Si—O3^x	109.60 (3)	O2^xix—O2—O2^xii	110.667 (17)
Sn—Ca—Sn^viii	107.068 (5)	O2^xix—O2—O3	128.147 (16)
Sn—Ca—Sn^xiv	61.596 (7)	O2^xix—O2—O3^xviii	74.154 (16)
Sn—Ca—Sn^x	115.709 (5)	O2^xix—O2—O3^vi	100.071 (17)
Sn—Ca—Si	149.202 (3)	O2^xix—O2—O3^xii	81.871 (15)
Sn—Ca—O1	30.798 (3)	O2^xix—O2—O3^vii	130.990 (17)
Sn—Ca—O2^viii	125.394 (10)	O2^xii—O2—O3	62.453 (14)
Sn—Ca—O2^x	151.260 (10)	O2^xii—O2—O3^xviii	56.207 (13)
Sn—Ca—O2^xii	76.438 (9)	O2^xii—O2—O3^vi	138.009 (15)
Sn—Ca—O2^xiii	133.653 (12)	O2^xii—O2—O3^xii	47.684 (11)
Sn—Ca—O3	79.184 (12)	O2^xii—O2—O3^vii	48.030 (11)
Sn—Ca—O3^xiv	83.006 (12)	O3—O2—O3^xviii	59.665 (16)
Sn—Ca—O3^xv	95.829 (13)	O3—O2—O3^vi	118.16 (2)
Sn—Ca—O3^vii	36.888 (9)	O3—O2—O3^xii	110.136 (17)
Sn^viii—Ca—Sn^xiv	115.709 (5)	O3—O2—O3^vii	84.977 (16)
Sn^viii—Ca—Sn^x	129.906 (12)	O3^xviii—O2—O3^vi	164.802 (16)
Sn^viii—Ca—Si	64.953 (6)	O3^xviii—O2—O3^xii	80.343 (15)
Sn^viii—Ca—O1	115.047 (6)	O3^xviii—O2—O3^vii	104.237 (18)
Sn^viii—Ca—O2^viii	37.217 (9)	O3^vi—O2—O3^xii	113.169 (14)
Sn^viii—Ca—O2^x	94.515 (13)	O3^vi—O2—O3^vii	90.202 (15)
Sn^viii—Ca—O2^xii	93.805 (9)	O3^xii—O2—O3^vii	50.571 (13)
Sn^viii—Ca—O2^xiii	73.082 (8)	Sn^x—O3—Si^ii	126.75 (3)
Sn^viii—Ca—O3	161.164 (15)	Sn^x—O3—Ca	97.658 (18)
Sn^viii—Ca—O3^xiv	37.444 (10)	Sn^x—O3—Ca^xv	91.414 (14)
Sn^viii—Ca—O3^xv	120.802 (9)	Sn^x—O3—O1	141.16 (2)
Sn^viii—Ca—O3^vii	80.333 (8)	Sn^x—O3—O1^ix	40.688 (8)
Sn^xiv—Ca—Sn^x	107.068 (5)	Sn^x—O3—O1^xv	45.054 (13)
Sn^xiv—Ca—Si	149.202 (3)	Sn^x—O3—O2	153.43 (2)
Sn^xiv—Ca—O1	30.798 (3)	Sn^x—O3—O2^xviii	120.174 (17)
Sn^xiv—Ca—O2^viii	151.260 (10)	Sn^x—O3—O2^x	45.229 (11)
Sn^xiv—Ca—O2^x	125.394 (10)	Sn^x—O3—O2^xii	91.355 (15)
Sn^xiv—Ca—O2^xii	133.653 (12)	Sn^x—O3—O2^xxii	44.569 (11)
Sn^xiv—Ca—O2^xiii	76.438 (9)	Sn^x—O3—O3^xviii	95.619 (17)
Sn^xiv—Ca—O3	83.006 (12)	Sn^x—O3—O3^xv	97.118 (17)
Sn^xiv—Ca—O3^xiv	79.184 (12)	Si^ii—O3—Ca	123.396 (18)
Sn^xiv—Ca—O3^xv	36.888 (9)	Si^ii—O3—Ca^xv	106.77 (2)
Sn^xiv—Ca—O3^vii	95.829 (13)	Si^ii—O3—O1	91.053 (19)
Sn^x—Ca—Si	64.953 (6)	Si^ii—O3—O1^ix	98.38 (2)
Sn^x—Ca—O1	115.047 (6)	Si^ii—O3—O1^xv	139.211 (17)
Sn^x—Ca—O2^viii	94.515 (13)	Si^ii—O3—O2	33.336 (13)
Sn^x—Ca—O2^x	37.217 (9)	Si^ii—O3—O2^xviii	35.524 (14)
Sn^x—Ca—O2^xii	73.082 (8)	Si^ii—O3—O2^x	151.25 (3)
Sn^x—Ca—O2^xiii	93.805 (9)	Si^ii—O3—O2^xii	78.646 (18)
Sn^x—Ca—O3	37.444 (10)	Si^ii—O3—O2^xxii	88.636 (19)
Sn^x—Ca—O3^xiv	161.164 (15)	Si^ii—O3—O3^xviii	35.201 (19)
Sn^x—Ca—O3^xv	80.333 (8)	Si^ii—O3—O3^xv	132.33 (2)
Sn^x—Ca—O3^vii	120.802 (9)	Ca—O3—Ca^xv	104.895 (17)
Si—Ca—O1	180.0 (5)	Ca—O3—O1	47.166 (14)
Si—Ca—O2^viii	32.056 (10)	Ca—O3—O1^ix	94.928 (14)
Si—Ca—O2^x	32.056 (10)	Ca—O3—O1^xv	96.349 (16)
Si—Ca—O2^xii	74.614 (10)	Ca—O3—O2	91.625 (14)
Si—Ca—O2^xiii	74.614 (10)	Ca—O3—O2^xviii	141.90 (2)
Si—Ca—O3	100.376 (13)	Ca—O3—O2^x	52.432 (13)
Si—Ca—O3^xiv	100.376 (13)	Ca—O3—O2^xii	65.746 (11)
Si—Ca—O3^xv	113.982 (11)	Ca—O3—O2^xxii	142.22 (2)
Si—Ca—O3^vii	113.982 (11)	Ca—O3—O3^xviii	123.130 (15)
O1—Ca—O2^viii	147.944 (10)	Ca—O3—O3^xv	56.859 (12)
O1—Ca—O2^x	147.944 (10)	Ca^xv—O3—O1	84.621 (13)
O1—Ca—O2^xii	105.386 (10)	Ca^xv—O3—O1^ix	130.647 (14)
O1—Ca—O2^xiii	105.386 (10)	Ca^xv—O3—O1^xv	47.977 (15)
O1—Ca—O3	79.624 (13)	Ca^xv—O3—O2	110.222 (18)
O1—Ca—O3^xiv	79.624 (13)	Ca^xv—O3—O2^xviii	72.100 (14)
O1—Ca—O3^xv	66.018 (11)	Ca^xv—O3—O2^x	101.306 (17)
O1—Ca—O3^vii	66.018 (11)	Ca^xv—O3—O2^xii	170.527 (17)
O2^viii—Ca—O2^x	64.113 (15)	Ca^xv—O3—O2^xxii	80.849 (13)
O2^viii—Ca—O2^xii	70.284 (14)	Ca^xv—O3—O3^xviii	129.773 (16)
O2^viii—Ca—O2^xiii	83.549 (15)	Ca^xv—O3—O3^xv	48.036 (10)
O2^viii—Ca—O3	124.740 (18)	O1—O3—O1^ix	137.327 (14)
O2^viii—Ca—O3^xiv	74.659 (14)	O1—O3—O1^xv	113.154 (16)
O2^viii—Ca—O3^xv	135.161 (16)	O1—O3—O2	59.288 (13)
O2^viii—Ca—O3^vii	88.845 (13)	O1—O3—O2^xviii	95.311 (17)
O2^x—Ca—O2^xii	83.549 (15)	O1—O3—O2^x	97.701 (16)
O2^x—Ca—O2^xiii	70.284 (14)	O1—O3—O2^xii	87.543 (12)
O2^x—Ca—O3	74.659 (14)	O1—O3—O2^xxii	164.719 (17)
O2^x—Ca—O3^xiv	124.740 (18)	O1—O3—O3^xviii	116.421 (15)
O2^x—Ca—O3^xv	88.845 (13)	O1—O3—O3^xv	52.820 (10)
O2^x—Ca—O3^vii	135.161 (16)	O1^ix—O3—O1^xv	85.742 (15)
O2^xii—Ca—O2^xiii	149.229 (17)	O1^ix—O3—O2	113.926 (18)
O2^xii—Ca—O3	70.015 (12)	O1^ix—O3—O2^xviii	116.147 (18)
O2^xii—Ca—O3^xiv	115.934 (11)	O1^ix—O3—O2^x	57.343 (13)
O2^xii—Ca—O3^xv	145.087 (11)	O1^ix—O3—O2^xii	54.392 (10)
O2^xii—Ca—O3^vii	52.818 (11)	O1^ix—O3—O2^xxii	57.678 (11)
O2^xiii—Ca—O3	115.934 (11)	O1^ix—O3—O3^xviii	63.176 (13)
O2^xiii—Ca—O3^xiv	70.015 (12)	O1^ix—O3—O3^xv	129.087 (17)
O2^xiii—Ca—O3^xv	52.818 (11)	O1^xv—O3—O2	158.10 (2)
O2^xiii—Ca—O3^vii	145.087 (11)	O1^xv—O3—O2^xviii	106.884 (16)
O3—Ca—O3^xiv	159.25 (2)	O1^xv—O3—O2^x	60.562 (14)
O3—Ca—O3^xv	75.105 (14)	O1^xv—O3—O2^xii	131.934 (19)
O3—Ca—O3^vii	96.352 (14)	O1^xv—O3—O2^xxii	59.386 (12)
O3^xiv—Ca—O3^xv	96.352 (14)	O1^xv—O3—O3^xviii	129.768 (16)
O3^xiv—Ca—O3^vii	75.105 (14)	O1^xv—O3—O3^xv	60.334 (12)
O3^xv—Ca—O3^vii	132.037 (18)	O2—O3—O2^xviii	56.784 (14)
Sn—O1—Sn^xiv	133.37 (3)	O2—O3—O2^x	137.645 (15)
Sn—O1—Si^xvii	116.714 (5)	O2—O3—O2^xii	69.864 (14)
Sn—O1—Si^ii	75.201 (5)	O2—O3—O2^xxii	121.96 (2)
Sn—O1—Ca	113.315 (15)	O2—O3—O3^xviii	58.849 (15)
Sn—O1—O2	47.360 (8)	O2—O3—O3^xv	108.743 (17)
Sn—O1—O2^xiv	129.100 (15)	O2^xviii—O3—O2^x	164.802 (16)
Sn—O1—O2^v	46.682 (11)	O2^xviii—O3—O2^xii	114.036 (19)
Sn—O1—O2^xvi	107.90 (2)	O2^xviii—O3—O2^xxii	75.763 (15)
Sn—O1—O3	100.890 (10)	O2^xviii—O3—O3^xviii	61.486 (16)
Sn—O1—O3^xvii	90.33 (2)	O2^xviii—O3—O3^xv	109.825 (18)
Sn—O1—O3^xiv	106.567 (10)	O2^x—O3—O2^xii	74.458 (14)
Sn—O1—O3^vi	44.596 (13)	O2^x—O3—O2^xxii	89.798 (15)
Sn—O1—O3^xv	165.744 (9)	O2^x—O3—O3^xviii	118.451 (19)
Sn—O1—O3^vii	49.662 (10)	O2^x—O3—O3^xv	72.588 (15)
Sn^xiv—O1—Si^xvii	75.201 (5)	O2^xii—O3—O2^xxii	107.349 (17)
Sn^xiv—O1—Si^ii	116.714 (5)	O2^xii—O3—O3^xviii	58.881 (13)
Sn^xiv—O1—Ca	113.315 (15)	O2^xii—O3—O3^xv	122.586 (15)
Sn^xiv—O1—O2	129.100 (15)	O2^xxii—O3—O3^xviii	70.549 (15)
Sn^xiv—O1—O2^xiv	47.360 (8)	O2^xxii—O3—O3^xv	118.057 (16)
Sn^xiv—O1—O2^v	107.90 (2)	O3^xviii—O3—O3^xv	167.116 (19)
Sn^xiv—O1—O2^xvi	46.682 (11)

Symmetry codes: (i) x, y−1, z; (ii) x+1/2, y−1/2, z; (iii) −x, −y+1, −z; (iv) −x−1/2, −y+1/2, −z; (v) −x, −y, −z; (vi) −x+1/2, y−1/2, −z+1/2; (vii) x−1/2, −y+1/2, z−1/2; (viii) x−1/2, y+1/2, z; (ix) x+1/2, y+1/2, z; (x) −x+1/2, y+1/2, −z+1/2; (xi) x, −y+1, z+1/2; (xii) −x+1/2, −y+1/2, −z; (xiii) x−1/2, −y+1/2, z+1/2; (xiv) −x, y, −z+1/2; (xv) −x+1/2, −y+1/2, −z+1; (xvi) x, −y, z+1/2; (xvii) x−1/2, y−1/2, z; (xviii) −x+1, y, −z+1/2; (xix) −x+1, −y, −z; (xx) x, y+1, z; (xxi) −x, y+1, −z+1/2; (xxii) x+1/2, −y+1/2, z+1/2.

 

Footnotes

¹Similar to titanite, literature descriptions of the structure of malayaite often use International Tables for Crystallography Vol. A setting A2/a (Aroyo et al., 2006). Transformation to the default setting of space group 15 used in this work is achieved by a change of axis c, −b, a and an appropriate origin shift e.g. 0, ½, 0 in Inorganic Crystal Structure Database entry No. 1042.