Crystal structures of Ca(ClO4)2·4H2O and Ca(ClO4)2·6H2O.

The title compounds, calcium perchlorate tetra-hydrate and calcium perchlorate hexa-hydrate, were crystallized at low temperatures according to the solid-liquid phase diagram. The structure of the tetra-hydrate consists of one Ca(2+) cation eightfold coordinated in a square-anti-prismatic fashion by four water mol-ecules and four O atoms of four perchlorate tetra-hedra, forming chains parallel to [01-1] by sharing corners of the ClO4 tetra-hedra. The structure of the hexa-hydrate contains two different Ca(2+) cations, each coordinated by six water mol-ecules and two O atoms of two perchlorate tetra-hedra, forming [Ca(H2O)6(ClO4)]2 dimers by sharing two ClO4 tetra-hedra. The dimers are arranged in sheets parallel (001) and alternate with layers of non-coordinating ClO4 tetra-hedra. O-H⋯O hydrogen bonds between the water mol-ecules as donor and ClO4 tetra-hedra and water mol-ecules as acceptor groups lead to the formation of a three-dimensional network in the two structures. Ca(ClO4)2·6H2O was refined as a two-component inversion twin, with an approximate twin component ratio of 1:1 in each of the two structures.

Chemical context

Since the detection of perchlorates on Mars during the Phoenix Mission (Chevrier et al., 2009 ▶), inter­est in these salts, and especially their hydrates, has risen considerably (Kim et al., 2013 ▶; Quinn et al., 2013 ▶; Kerr, 2013 ▶; Davila et al., 2013 ▶; Schuttlefield et al., 2011 ▶; Navarro-González et al., 2010 ▶; Marion et al., 2010 ▶). To gain more knowledge about the behavior of salts and salt hydrates, it is essential to determine the corresponding phase diagrams. For calcium perchlorate, this was performed by several authors (Marion et al., 2010 ▶; Pestova et al., 2005 ▶; Dobrynina, 1984 ▶; Lilich & Djurinskii, 1956 ▶; Nicholson & Felsing, 1950 ▶; Willard & Smith, 1923 ▶) for different concentration areas with different results. The stable salt hydrate phase at room temperature in this system is calcium perchlorate tetra­hydrate. At lower temperatures, a higher hydrated phase, i.e. the hexa­hydrate, occurs as the stable phase.

Structural commentary

The Ca2+ cation in Ca(ClO4)·4H2O is coordinated by four water mol­ecules (O1, O2, O7, O8) and four O atoms from two pairs of symmetry-related perchlorate tetra­hedra as shown in Fig. 1 ▶ a. The resulting coordination polyhedron is a distorted square anti-prism (Fig. 1 ▶ b). The Ca—O bond lengths involving the water mol­ecules range from 2.3284 (17) to 2.4153 (16) Å and are considerably shorter than the Ca—O bond lengths involving the perchlorate O atoms [2.5417 (16) to 2.5695 (17) Å].

Figure 1

(a) The principle building block in the structure of Ca(ClO4)2·4H2O and (b) the square anti-prismatic coordination of Ca2+. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) 1 − x, −y, 1 − z; (ii) 1 − x, 1 − y, 2 − z.]

The two different Ca2+ cations in Ca(ClO4)·6H2O are each coordinated by six water mol­ecules and two perchlorate tetra­hedra (Fig. 2 ▶). Again, the bond lengths between the cations and water mol­ecules [2.319 (6)–2.500 (6) Å] are shorter than those to the perchlorate groups. For the latter, one of the two distances for each of the Ca2+ cations is by 0.5 Å markedly longer than the other (∼3.07 versus ∼2.53 Å). Nevertheless, according to the bond-valence model (Brown, 2002 ▶), the longer bond contributes ca. 0.05 valence units to the overall bond-valence sum and hence should not be neglected. If this longer bond is considered to be relevant, again a square anti-prismatic coordination polyhedron is realised for both Ca2+ cations, however with a much greater distortion. Two perchlorate tetra­hedra in the hexa­hydrate are shared between two Ca2+ ions, leading to the formation of [Ca(H2O)6(ClO4)]2 dimers oriented in layers parallel to (001).

Figure 2

The principle building blocks in the structure of Ca(ClO4)2·6H2O. Displacement ellipsoids are drawn at the 50% probability level.

Supra­molecular features

The perchlorate tetra­hedra in the structure of Ca(ClO4)·4H2O are shared between two adjacent Ca2+ ions, forming chains extending parallel to [01] (Fig. 3 ▶) whereby each Ca2+ ion is connected along the chain on one side with a pair of Cl1 perchlorate tetra­hedra, and on the opposite side with a pair of Cl2 perchlorate tetra­hedra. The chains are arranged in sheets parallel to (01) and are linked by O—H⋯O hydrogen bonds into a three-dimensional network with similar O⋯O distances between the water mol­ecules and the perchlorate tetra­hedra (Table 1 ▶).

Figure 3

Formation of sheets and inter­connection of chains via hydrogen bonds in Ca(ClO4)2·4H2O. Only the strongest hydrogen bonds are shown, represented by dashed lines.

Table 1

Hydrogen-bond geometry (, ) for Ca(ClO4)24H2O

DHA	DH	HA	D A	DHA
O1H1BO11i	0.82(1)	2.11(2)	2.888(2)	158(3)
O1H1AO3ii	0.82(1)	2.13(1)	2.947(2)	174(3)
O2H2AO11iii	0.82(1)	2.17(2)	2.947(2)	159(3)
O2H2BO4iv	0.82(1)	2.02(1)	2.830(2)	172(3)
O7H7BO4	0.81(1)	2.22(2)	2.924(2)	146(3)
O7H7AO1iii	0.82(1)	2.06(1)	2.870(2)	172(3)
O8H8AO4v	0.82(1)	2.33(3)	2.986(2)	137(4)
O8H8BO2vi	0.82(1)	2.14(1)	2.950(2)	169(5)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .

In addition to the two coordinating perchlorate tetra­hedra in Ca(ClO4)·6H2O, two ‘free’ perchlorate tetra­hedra are present in the crystal structure. These ‘free’ ClO4 tetra­hedra are arranged in sheets and alternate with the [Ca(H2O)6(ClO4)]2 sheets along [001] (Fig. 4 ▶). The ‘free’ perchlorate tetra­hedra are connected to the dimers via O—H⋯O hydrogen bonds, as shown in Fig. 4 ▶. The dimers are additionally connected through further O—H⋯O hydrogen bonds (Table 2 ▶) into a three-dimensional network (Fig. 5 ▶).

Figure 4

Formation of perchlorate-bridged dimers in Ca(ClO4)2·6H2O and location of ‘free’ perchlorate tetra­hedra in the gaps between the dimers (highlighted in dark green). Only the strongest hydrogen bonds are shown, represented by dashed lines.

Table 2

Hydrogen-bond geometry (, ) for Ca(ClO4)26H2O

DHA	DH	HA	D A	DHA
O1H1AO15	0.84(2)	2.07(3)	2.887(10)	164(8)
O1H1BO5i	0.84(2)	2.25(5)	2.915(7)	136(6)
O1H1BO16i	0.84(2)	2.44(5)	3.132(10)	140(6)
O2H2AO23ii	0.84(2)	2.03(2)	2.856(9)	169(7)
O2H2BO26iii	0.84(2)	2.14(3)	2.932(8)	155(6)
O3H3AO12iv	0.84(2)	2.07(2)	2.899(8)	168(8)
O3H3BO19iii	0.84(2)	2.15(3)	2.934(8)	156(7)
O4H4AO27	0.84(2)	2.28(3)	3.074(11)	158(8)
O4H4BO28iii	0.84(2)	2.36(3)	3.177(10)	163(8)
O5H5AO2iv	0.84(2)	1.98(3)	2.783(8)	159(7)
O5H5BO19	0.84(2)	2.20(5)	2.903(9)	142(6)
O6H6AO8v	0.84(2)	2.18(4)	2.925(7)	149(7)
O6H6BO19	0.84(2)	2.08(3)	2.891(10)	162(8)
O7H7AO23vi	0.84(2)	2.29(4)	3.042(9)	149(6)
O7H7BO24vii	0.84(2)	2.50(5)	3.199(9)	141(6)
O7H7BO27viii	0.84(2)	2.57(5)	3.242(11)	138(6)
O8H8AO10ix	0.84(2)	2.08(4)	2.805(8)	145(6)
O8H8BO15	0.84(2)	2.07(3)	2.879(9)	162(7)
O9H9AO27x	0.84(2)	2.06(3)	2.865(10)	161(7)
O9H9BO21vi	0.84(2)	2.23(5)	2.962(10)	145(7)
O10H10AO21vii	0.84(2)	2.12(3)	2.930(9)	163(7)
O10H10BO28x	0.84(2)	2.10(3)	2.902(10)	162(7)
O11H11AO9ix	0.84(2)	2.14(4)	2.893(9)	150(7)
O11H11BO15xi	0.84(2)	2.11(3)	2.915(9)	161(7)
O12H12AO26	0.84(2)	2.35(5)	2.995(9)	135(6)
O12H12AO20	0.84(2)	2.40(4)	3.102(9)	142(6)
O12H12BO24ii	0.84(2)	2.03(2)	2.861(9)	171(7)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) ; (x) ; (xi) .

Figure 5

Formation of layers parallel to (001) in Ca(ClO4)2·6H2O. Only the strongest hydrogen bonds are shown, represented by dashed lines.

Database survey

For crystal structures of other M(ClO4)2·4H2O phases, see: Robertson & Bish (2010 ▶; M = Mg); Hennings et al. (2014 ▶; Sr); Solovyov (2012 ▶; Mg); Johansson (1966 ▶; Hg). For crystal structures of other M(ClO4)2·6H2O phases, see: Ghosh et al. (1997 ▶; M = Ni, Zn); Ghosh & Ray (1981 ▶; Fe); Johansson et al. (1978 ▶; Hg); Mani & Ramaseshan (1961 ▶; Cu); Johansson & Sandström (1987 ▶; Cd); Gallucci & Gerkin (1989 ▶; Cu); West (1935 ▶; Mg).

Synthesis and crystallization

Ca(ClO4)2·4H2O was crystallized from an aqueous solution of 62.96 wt% Ca(ClO4)2 at 273 K after one day and Ca(ClO4)2·6H2O from an aqueous solution of 57.55 wt% Ca(ClO4)2 at 238 K after one week. For the preparation of these aqueous solutions, Ca(ClO4)2·4H2O (Acros Organics, p.A.) was used. The Ca2+ content was analysed via complexometric titration with EDTA. The crystals remain stable in the saturated aqueous solution over at least four weeks.

The samples were stored in a freezer or a cryostat at low temperatures. The crystals were separated and embedded in perfluorinated ether for X-ray analysis.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▶. The H atoms of each structure were placed in the positions indicated by difference Fourier maps. For Ca(ClO4)2·4H2O, distance restraints were applied for all water mol­ecules, with O—H and H—H distance restraints of 0.82 (1) and 1.32 (1) Å, respectively. For Ca(ClO4)2·6H2O, U iso values were set at 1.2U eq(O) using a riding-model approximation. Distance restraints were applied for that structure for all water mol­ecules, with O—H and H—H distance restraints of 0.84 (2) and 1.4 (2) Å, respectively. Ca(ClO4)2·6H2O was refined as a two-component inversion twin, with an approximate twin component ratio of 1:1.

Table 3

Experimental details

	Ca(ClO4)24H2O	Ca(ClO4)26H2O
Crystal data
M r	311.04	347.08
Crystal system, space group	Triclinic, P	Orthorhombic, P c a21
Temperature (K)	200	180
a, b, c ()	5.4886(11), 7.8518(15), 11.574(2)	10.9603(4), 7.9667(7), 26.7735(18)
, , ()	99.663(16), 90.366(16), 90.244(16)	90, 90, 90
V (3)	491.71(17)	2337.8(3)
Z	2	8
Radiation type	Mo K	Mo K
(mm1)	1.24	1.06
Crystal size (mm)	0.04 0.03 0.02	0.38 0.31 0.08
Data collection
Diffractometer	Stoe IPDS2	Stoe IPDS2
Absorption correction	Integration Coppens (1970 ▶)	Integration (Coppens, 1970 ▶)
T min, T max	0.644, 0.789	0.684, 0.923
No. of measured, independent and observed [I > 2(I)] reflections	2659, 2636, 2529	15755, 5326, 4919
R int	0.074	0.062
(sin /)max (1)	0.686	0.650
Refinement
R[F 2 > 2(F 2)], wR(F 2), S	0.031, 0.089, 1.20	0.042, 0.113, 1.09
No. of reflections	2636	5326
No. of parameters	168	380
No. of restraints	12	37
H-atom treatment	All H-atom parameters refined	Only H-atom coordinates refined
max, min (e 3)	0.36, 0.75	0.41, 0.67
Absolute structure		Refined as an inversion twin
Absolute structure parameter		0.45(9)

Computer programs: X-AREA and X-RED (Stoe Cie, 2009 ▶), SHELXS97 and SHELXL2012 (Sheldrick, 2008 ▶), DIAMOND (Brandenburg, 2006 ▶) and publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) CaClO4_4H2O_200K, CaClO4_6H2O_180K. DOI: 10.1107/S1600536814024532/wm5079sup1.cif

Structure factors: contains datablock(s) CaClO4_4H2O_200K. DOI: 10.1107/S1600536814024532/wm5079CaClO4_4H2O_200Ksup2.hkl

Structure factors: contains datablock(s) CaClO4_6H2O_180K. DOI: 10.1107/S1600536814024532/wm5079CaClO4_6H2O_180Ksup3.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S1600536814024532/wm5079CaClO4_4H2O_200Ksup4.cml

Click here for additional data file.

Supporting information file. DOI: 10.1107/S1600536814024532/wm5079CaClO4_6H2O_180Ksup5.cml

CCDC references: 1033323, 1033324

Additional supporting information: crystallographic information; 3D view; checkCIF report

Ca(ClO4)2·6H2O	Dx = 1.972 Mg m−3
Mr = 347.08	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pca21	Cell parameters from 17254 reflections
a = 10.9603 (4) Å	θ = 2.9–29.6°
b = 7.9667 (7) Å	µ = 1.06 mm−1
c = 26.7735 (18) Å	T = 180 K
V = 2337.8 (3) Å3	Plate, colourless
Z = 8	0.38 × 0.31 × 0.08 mm
F(000) = 1424

Stoe IPDS-2 diffractometer	5326 independent reflections
Radiation source: fine-focus sealed tube	4919 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.062
Detector resolution: 6.67 pixels mm-1	θmax = 27.5°, θmin = 1.5°
rotation method scans	h = −15→15
Absorption correction: integration (Coppens, 1970)	k = −11→9
Tmin = 0.684, Tmax = 0.923	l = −37→37
15755 measured reflections

Refinement on F2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	Only H-atom coordinates refined
R[F2 > 2σ(F2)] = 0.042	w = 1/[σ2(Fo2) + (0.0687P)2 + 2.3411P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.113	(Δ/σ)max < 0.001
S = 1.09	Δρmax = 0.41 e Å−3
5326 reflections	Δρmin = −0.67 e Å−3
380 parameters	Absolute structure: Refined as an inversion twin
37 restraints	Absolute structure parameter: 0.45 (9)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refined as a 2-component inversion twin.

	x	y	z	Uiso*/Ueq
Ca1	0.87471 (15)	0.02736 (19)	0.29261 (6)	0.0110 (3)
Ca2	0.87640 (16)	0.47462 (18)	0.07672 (6)	0.0112 (3)
Cl3	0.7770 (2)	0.50239 (14)	0.39582 (8)	0.0102 (5)
Cl4	0.79753 (11)	0.06649 (15)	0.13985 (8)	0.0110 (2)
Cl1	0.95348 (11)	0.43473 (15)	0.22917 (8)	0.0109 (2)
Cl2	0.0260 (2)	0.99991 (14)	0.47324 (8)	0.0128 (5)
O5	0.7128 (5)	0.2189 (8)	0.2859 (2)	0.0169 (11)
H5B	0.714 (6)	0.295 (6)	0.264 (2)	0.020*
H5A	0.660 (5)	0.209 (10)	0.3081 (19)	0.020*
O3	0.7416 (5)	−0.1972 (7)	0.2841 (2)	0.0185 (12)
H3A	0.672 (3)	−0.190 (10)	0.296 (3)	0.022*
H3B	0.752 (7)	−0.274 (6)	0.263 (2)	0.022*
O7	0.9726 (7)	0.4844 (6)	−0.0075 (3)	0.0162 (14)
H7B	0.995 (7)	0.557 (7)	−0.028 (2)	0.019*
H7A	0.989 (6)	0.406 (6)	−0.027 (2)	0.019*
O8	1.0380 (5)	0.2796 (7)	0.0823 (2)	0.0132 (10)
H8A	1.094 (4)	0.245 (8)	0.064 (2)	0.016*
H8B	1.013 (6)	0.186 (4)	0.093 (2)	0.016*
O6	0.7539 (4)	0.6064 (6)	0.13676 (16)	0.0190 (8)
H6B	0.761 (7)	0.565 (10)	0.1655 (14)	0.023*
H6A	0.684 (3)	0.648 (9)	0.133 (3)	0.023*
O1	0.9967 (4)	−0.1049 (6)	0.23219 (17)	0.0186 (8)
H1A	0.987 (7)	−0.060 (10)	0.2041 (15)	0.022*
H1B	1.0726 (17)	−0.118 (9)	0.232 (3)	0.022*
O2	0.9964 (5)	−0.1849 (7)	0.3393 (2)	0.0119 (11)
H2A	1.007 (7)	−0.184 (9)	0.3702 (7)	0.014*
H2B	0.967 (6)	−0.281 (4)	0.335 (2)	0.014*
O4	0.7803 (9)	0.0171 (8)	0.3739 (3)	0.0262 (18)
H4B	0.793 (8)	−0.068 (6)	0.392 (3)	0.031*
H4A	0.795 (7)	0.093 (7)	0.395 (2)	0.031*
O15	0.9234 (8)	0.0045 (5)	0.1339 (4)	0.0152 (16)
O14	0.7230 (8)	−0.0046 (5)	0.1019 (3)	0.0194 (18)
O19	0.8302 (8)	0.4971 (5)	0.2349 (3)	0.0142 (15)
O20	1.0316 (9)	0.5052 (6)	0.2678 (4)	0.027 (2)
O26	0.8567 (9)	0.5044 (5)	0.3525 (3)	0.0215 (19)
O12	1.0148 (5)	0.2008 (7)	0.3398 (2)	0.0129 (11)
H12B	1.034 (7)	0.189 (9)	0.3699 (10)	0.016*
H12A	1.006 (6)	0.303 (3)	0.334 (2)	0.016*
O16	0.7540 (9)	0.0215 (7)	0.1877 (3)	0.0234 (15)
O21	0.1020 (10)	0.9989 (6)	0.5168 (3)	0.026 (2)
O28	0.7947 (7)	0.6558 (9)	0.4237 (3)	0.0231 (15)
O27	0.8080 (7)	0.3589 (9)	0.4260 (3)	0.0260 (16)
O23	0.0566 (6)	0.8560 (8)	0.4423 (3)	0.0183 (13)
O24	0.0519 (7)	1.1496 (9)	0.4444 (3)	0.0212 (14)
O18	0.9975 (9)	0.4783 (7)	0.1797 (3)	0.0223 (14)
O13	0.7991 (3)	0.2473 (5)	0.13424 (18)	0.0150 (8)
O17	0.9520 (4)	0.2544 (5)	0.23441 (19)	0.0158 (8)
O9	0.7381 (6)	0.2976 (8)	0.0297 (2)	0.0171 (12)
H9A	0.721 (7)	0.338 (8)	0.0016 (13)	0.021*
H9B	0.753 (7)	0.195 (3)	0.025 (3)	0.021*
O22	−0.0976 (9)	0.9933 (7)	0.4886 (5)	0.034 (2)
O25	0.6508 (8)	0.4900 (7)	0.3824 (5)	0.034 (2)
O10	0.7580 (5)	0.6907 (7)	0.0295 (2)	0.0139 (11)
H10B	0.746 (7)	0.658 (8)	0.0002 (11)	0.017*
H10A	0.783 (6)	0.789 (4)	0.025 (2)	0.017*
O11	1.0097 (5)	0.7020 (8)	0.0838 (3)	0.0192 (12)
H11A	1.079 (3)	0.736 (9)	0.075 (3)	0.023*
H11B	0.987 (7)	0.799 (4)	0.092 (3)	0.023*

	U11	U22	U33	U12	U13	U23
Ca1	0.0083 (6)	0.0090 (5)	0.0157 (7)	0.0010 (5)	0.0018 (4)	−0.0005 (7)
Ca2	0.0095 (6)	0.0084 (5)	0.0155 (7)	0.0010 (5)	0.0021 (4)	0.0016 (7)
Cl3	0.0096 (11)	0.0097 (11)	0.0113 (11)	−0.0005 (4)	0.0016 (10)	0.0004 (4)
Cl4	0.0127 (5)	0.0095 (6)	0.0108 (5)	−0.0007 (4)	0.0020 (4)	0.0012 (5)
Cl1	0.0124 (6)	0.0080 (6)	0.0122 (5)	−0.0018 (4)	0.0019 (4)	0.0008 (5)
Cl2	0.0180 (13)	0.0098 (11)	0.0105 (11)	−0.0001 (4)	0.0016 (11)	0.0002 (4)
O5	0.015 (2)	0.015 (2)	0.020 (2)	0.0012 (19)	0.0022 (19)	0.0054 (19)
O3	0.019 (3)	0.013 (2)	0.024 (2)	−0.007 (2)	0.007 (2)	−0.0047 (18)
O7	0.022 (3)	0.019 (3)	0.008 (3)	0.0018 (18)	0.009 (2)	−0.0048 (16)
O8	0.011 (2)	0.0077 (19)	0.020 (2)	0.0033 (17)	0.0061 (18)	−0.0006 (17)
O6	0.0201 (19)	0.024 (2)	0.0130 (16)	0.0123 (17)	0.0008 (17)	0.0029 (18)
O1	0.0196 (19)	0.021 (2)	0.0151 (17)	0.0079 (17)	0.0003 (17)	0.0028 (18)
O2	0.017 (2)	0.009 (2)	0.009 (2)	−0.0002 (19)	−0.0009 (17)	0.0010 (17)
O4	0.033 (4)	0.023 (3)	0.023 (4)	0.000 (2)	0.008 (3)	0.006 (2)
O15	0.014 (4)	0.010 (3)	0.022 (4)	0.0049 (13)	−0.001 (3)	−0.0002 (14)
O14	0.019 (4)	0.019 (4)	0.021 (4)	−0.0067 (15)	0.000 (3)	−0.0045 (15)
O19	0.013 (4)	0.019 (3)	0.011 (3)	0.0049 (14)	0.007 (3)	0.0011 (13)
O20	0.027 (5)	0.023 (4)	0.033 (5)	−0.0106 (18)	−0.016 (4)	−0.0050 (18)
O26	0.034 (5)	0.011 (3)	0.020 (4)	−0.0004 (16)	0.014 (4)	0.0002 (14)
O12	0.016 (2)	0.011 (2)	0.013 (2)	0.0011 (19)	−0.0010 (17)	0.0021 (18)
O16	0.027 (3)	0.022 (2)	0.021 (3)	0.001 (2)	0.015 (2)	0.011 (2)
O21	0.035 (5)	0.029 (4)	0.013 (4)	0.0009 (18)	−0.010 (4)	0.0018 (15)
O28	0.037 (4)	0.011 (3)	0.021 (3)	−0.004 (2)	0.002 (3)	−0.005 (2)
O27	0.042 (4)	0.017 (3)	0.019 (3)	0.008 (3)	0.003 (3)	0.008 (3)
O23	0.027 (3)	0.014 (3)	0.015 (3)	0.002 (2)	0.001 (2)	−0.006 (2)
O24	0.034 (3)	0.012 (3)	0.017 (3)	−0.003 (2)	−0.006 (2)	0.008 (2)
O18	0.025 (3)	0.027 (2)	0.015 (3)	0.001 (2)	0.012 (2)	0.002 (2)
O13	0.0195 (19)	0.0081 (18)	0.017 (2)	0.0011 (14)	0.0007 (15)	0.0020 (15)
O17	0.0197 (19)	0.0074 (17)	0.020 (2)	−0.0009 (15)	−0.0007 (15)	0.0014 (16)
O9	0.025 (3)	0.011 (2)	0.016 (2)	−0.003 (2)	−0.003 (2)	0.0006 (19)
O22	0.024 (5)	0.032 (4)	0.044 (6)	0.0013 (19)	0.013 (4)	0.000 (2)
O25	0.010 (4)	0.038 (4)	0.054 (6)	−0.0011 (19)	−0.014 (4)	0.004 (2)
O10	0.012 (2)	0.014 (2)	0.016 (2)	0.0008 (19)	0.0021 (18)	0.0005 (18)
O11	0.016 (3)	0.015 (2)	0.027 (2)	−0.002 (2)	0.000 (2)	−0.0030 (19)

Ca1—O3	2.319 (6)	Cl3—O25	1.432 (9)
Ca1—O5	2.347 (6)	Cl3—O27	1.440 (7)
Ca1—O1	2.349 (5)	Cl3—O28	1.446 (7)
Ca1—O4	2.412 (9)	Cl3—O26	1.452 (9)
Ca1—O12	2.421 (6)	Cl4—O16	1.414 (8)
Ca1—O2	2.490 (6)	Cl4—O14	1.421 (8)
Ca1—O17	2.533 (5)	Cl4—O13	1.449 (4)
Ca1—O16	3.104 (9)	Cl4—O15	1.474 (8)
Ca2—O11	2.335 (6)	Cl1—O17	1.444 (4)
Ca2—O6	2.343 (5)	Cl1—O19	1.448 (8)
Ca2—O8	2.360 (5)	Cl1—O18	1.451 (8)
Ca2—O9	2.423 (6)	Cl1—O20	1.455 (9)
Ca2—O7	2.491 (7)	Cl2—O22	1.416 (10)
Ca2—O10	2.500 (6)	Cl2—O21	1.433 (10)
Ca2—O13	2.523 (4)	Cl2—O24	1.449 (7)
Ca2—O18	3.061 (9)	Cl2—O23	1.453 (7)
O3—Ca1—O5	91.1 (3)	O7—Ca2—O10	74.9 (2)
O3—Ca1—O1	86.81 (19)	O11—Ca2—O13	135.8 (2)
O5—Ca1—O1	132.0 (2)	O6—Ca2—O13	73.17 (15)
O3—Ca1—O4	78.0 (2)	O8—Ca2—O13	75.00 (17)
O5—Ca1—O4	76.5 (3)	O9—Ca2—O13	71.91 (17)
O1—Ca1—O4	148.3 (2)	O7—Ca2—O13	135.81 (17)
O3—Ca1—O12	152.9 (2)	O10—Ca2—O13	128.95 (17)
O5—Ca1—O12	98.5 (2)	O11—Ca2—O18	69.4 (2)
O1—Ca1—O12	104.72 (19)	O6—Ca2—O18	68.03 (19)
O4—Ca1—O12	79.7 (3)	O8—Ca2—O18	67.9 (2)
O3—Ca1—O2	82.1 (2)	O9—Ca2—O18	138.2 (2)
O5—Ca1—O2	152.3 (2)	O7—Ca2—O18	129.2 (3)
O1—Ca1—O2	74.68 (18)	O10—Ca2—O18	132.42 (19)
O4—Ca1—O2	75.8 (2)	O13—Ca2—O18	66.58 (17)
O12—Ca1—O2	77.7 (2)	O25—Cl3—O27	108.3 (5)
O3—Ca1—O17	134.5 (2)	O25—Cl3—O28	108.5 (5)
O5—Ca1—O17	75.01 (18)	O27—Cl3—O28	110.4 (5)
O1—Ca1—O17	72.92 (15)	O25—Cl3—O26	112.4 (7)
O4—Ca1—O17	136.29 (19)	O27—Cl3—O26	108.3 (4)
O12—Ca1—O17	72.61 (17)	O28—Cl3—O26	108.8 (4)
O2—Ca1—O17	127.91 (18)	O16—Cl4—O14	110.7 (5)
O3—Ca1—O16	68.4 (2)	O16—Cl4—O13	110.5 (3)
O5—Ca1—O16	67.5 (2)	O14—Cl4—O13	109.2 (3)
O1—Ca1—O16	67.2 (2)	O16—Cl4—O15	109.2 (5)
O4—Ca1—O16	129.3 (3)	O14—Cl4—O15	109.1 (5)
O12—Ca1—O16	138.63 (19)	O13—Cl4—O15	108.1 (3)
O2—Ca1—O16	132.21 (19)	O17—Cl1—O19	108.7 (3)
O17—Ca1—O16	66.22 (16)	O17—Cl1—O18	109.3 (3)
O11—Ca2—O6	87.4 (2)	O19—Cl1—O18	109.0 (5)
O11—Ca2—O8	92.1 (3)	O17—Cl1—O20	108.8 (3)
O6—Ca2—O8	133.0 (2)	O19—Cl1—O20	110.0 (5)
O11—Ca2—O9	152.3 (2)	O18—Cl1—O20	111.1 (5)
O6—Ca2—O9	105.0 (2)	O22—Cl2—O21	108.6 (7)
O8—Ca2—O9	96.8 (2)	O22—Cl2—O24	111.9 (4)
O11—Ca2—O7	77.6 (2)	O21—Cl2—O24	108.9 (4)
O6—Ca2—O7	148.20 (18)	O22—Cl2—O23	110.9 (4)
O8—Ca2—O7	76.1 (2)	O21—Cl2—O23	108.9 (4)
O9—Ca2—O7	79.2 (2)	O24—Cl2—O23	107.5 (5)
O11—Ca2—O10	80.3 (2)	Cl4—O16—Ca1	132.3 (5)
O6—Ca2—O10	75.00 (17)	Cl1—O18—Ca2	132.5 (5)
O8—Ca2—O10	151.0 (2)	Cl4—O13—Ca2	141.3 (3)
O9—Ca2—O10	79.2 (3)	Cl1—O17—Ca1	140.7 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O15	0.84 (2)	2.07 (3)	2.887 (10)	164 (8)
O1—H1B···O5i	0.84 (2)	2.25 (5)	2.915 (7)	136 (6)
O1—H1B···O16i	0.84 (2)	2.44 (5)	3.132 (10)	140 (6)
O2—H2A···O23ii	0.84 (2)	2.03 (2)	2.856 (9)	169 (7)
O2—H2B···O26iii	0.84 (2)	2.14 (3)	2.932 (8)	155 (6)
O3—H3A···O12iv	0.84 (2)	2.07 (2)	2.899 (8)	168 (8)
O3—H3B···O19iii	0.84 (2)	2.15 (3)	2.934 (8)	156 (7)
O4—H4A···O27	0.84 (2)	2.28 (3)	3.074 (11)	158 (8)
O4—H4B···O28iii	0.84 (2)	2.36 (3)	3.177 (10)	163 (8)
O5—H5A···O2iv	0.84 (2)	1.98 (3)	2.783 (8)	159 (7)
O5—H5B···O19	0.84 (2)	2.20 (5)	2.903 (9)	142 (6)
O6—H6A···O8v	0.84 (2)	2.18 (4)	2.925 (7)	149 (7)
O6—H6B···O19	0.84 (2)	2.08 (3)	2.891 (10)	162 (8)
O7—H7A···O23vi	0.84 (2)	2.29 (4)	3.042 (9)	149 (6)
O7—H7B···O24vii	0.84 (2)	2.50 (5)	3.199 (9)	141 (6)
O7—H7B···O27viii	0.84 (2)	2.57 (5)	3.242 (11)	138 (6)
O8—H8A···O10ix	0.84 (2)	2.08 (4)	2.805 (8)	145 (6)
O8—H8B···O15	0.84 (2)	2.07 (3)	2.879 (9)	162 (7)
O9—H9A···O27x	0.84 (2)	2.06 (3)	2.865 (10)	161 (7)
O9—H9B···O21vi	0.84 (2)	2.23 (5)	2.962 (10)	145 (7)
O10—H10A···O21vii	0.84 (2)	2.12 (3)	2.930 (9)	163 (7)
O10—H10B···O28x	0.84 (2)	2.10 (3)	2.902 (10)	162 (7)
O11—H11A···O9ix	0.84 (2)	2.14 (4)	2.893 (9)	150 (7)
O11—H11B···O15xi	0.84 (2)	2.11 (3)	2.915 (9)	161 (7)
O12—H12A···O26	0.84 (2)	2.35 (5)	2.995 (9)	135 (6)
O12—H12A···O20	0.84 (2)	2.40 (4)	3.102 (9)	142 (6)
O12—H12B···O24ii	0.84 (2)	2.03 (2)	2.861 (9)	171 (7)