Crystal structure of the inter­metallic compound SrCdPt

The crystal structure of the title compound, strontium cadmium platinum, adopts the TiNiSi structure type with the Sr atoms on the Ti, the Cd atoms on the Ni and the Pt atoms on the Si positions, respectively. The Pt atoms form cadmium-centred tetra­hedra that are condensed into a three-dimensional network with channels parallel to the b-axis direction in which the Sr atoms are located. The latter are bonded to each other in the form of six-membered rings with chair conformations. All atoms in the SrCdPt structure are situated on a mirror plane.

1. Chemical context

Exploratory synthesis of polar inter­metallic phases has proven to be productive in terms of novel compositions, new and unprecedented structures, and unusual bonding regimes (Corbett, 2010). Platinum has participated significantly in the formation of ternary inter­metallic compounds. Together with indium, a number of platinum phases have been reported, for example BaPtIn₃ (Palasyuk & Corbett, 2007), SrPtIn (Hoffmann & Pöttgen, 1999), CaPtIn₂ (Hoffmann et al., 1999) or Ca₂Pt₂In (Muts et al., 2007). Some other ternary inter­metallic compounds of platinum with cadmium, viz. Ca₂CdPt₂ (Samal & Corbett, 2012), Ca₆Pt₈Cd₁₆, (Ba/Sr)Cd₄Pt₂ (Samal et al., 2013), Ca₆Cd₁₁Pt (Gulo et al., 2013) and CaCdPt (Kersting et al., 2013) have been isolated recently. They demonstrate the diversity of the structures types adopted. In this communication, we present the crystal structure of SrCdPt.

2. Structural commentary

SrCdPt crystallizes in the TiNiSi structure type. The titanium, nickel, and silicon sites are occupied by strontium, cadmium, and platinum, respectively, in the structure of the title compound. Although platinum and nickel are in the same group in the periodic table, the platinum in SrCdPt occupies the silicon site and not the nickel site because platinum is the most electronegative metal in this structure, just like silicon in TiNiSi. A count of 56 valence electrons per cell is found in SrCdPt [(Sr:2 + Cd:2 +Pt:10) × 4] whilst TiNiSi contains only 32 valence electrons per cell.

In the compounds of the TiNiSi structure family, the metals listed first in the formula are linked to each other, forming six-membered rings in chair, half-chair, or boat conformations. The adopted conformation is not a function of the electron count, but is due to the nature of the respective metal (Landrum et al., 1998). In the SrCdPt structure, the strontium atoms construct six-membered rings with chair conformations and Sr—Sr distances of 3.870 (2) Å, which is significantly shorter than the sum of the covalent radii of 4.30 Å (Emsley, 1999), indicating strong bonding inter­actions between them (Fig. 1). The existence of such strong Sr—Sr bonds is not noticeable in SrCd₄Pt₂ (Samal et al., 2013). The platinum atoms in the structure of SrCdPt form zigzag chains of edge-sharing cadmium-centred tetra­hedra parallel to the b-axis direction. These chains are condensed via common corners with adjacent chains, building up the three-dimensional network with channels parallel to the b-axis direction in which the Sr atoms reside, as illustrated in Fig. 2.

Figure 1 Projection of the crystal structure of SrCdPt approximately along [100]. Displacement ellipsoids are represented at the 90% probability level.

Figure 2 View of zigzag chains of cadmium-centred tetra­hedra of Pt atoms forming channels along the b-axis direction in the structure of SrCdPt.

Strontium has an overall coordination number of 15 and is surrounded by four other strontium, six cadmium, and five platinum atoms. The Sr—Cd distances range from 3.3932 (13) to 3.6124 (17) Å, whereas the Sr—Pt distances vary only slightly, from 3.1943 (11) to 3.2238 (10) Å. Cadmium is located at a site that is surrounded by six strontium and four platinum atoms, whilst platinum has a coordination number of 9 defined by five strontium and four cadmium atoms. The environment of each atom in this structure is represented in Fig. 3. The inter­atomic distances (Sr—Cd, Sr—Pt, and Cd—Pt) are in good agreement with those found in the structures of some other ternary compounds in the alkaline earth–Cd–Pt system (Samal & Corbett, 2012; Samal et al., 2013; Gulo et al., 2013; Kersting et al., 2013). In SrCdPt, the shortest Cd—Cd distance of 3.3197 (15) Å is too long to be considered as a bond. It is significantly longer than the sum of the covalent radii of 2.90 Å (Emsley, 1999). In contrast, cadmium atoms are bonded together, forming Cd₄ tetra­hedra in SrCd₄Pt₂, Cd₈ tetra­hedral stars in Ca₆Cd₁₆Pt₈, and Cd₇ penta­gonal bipyramids in Ca₆Cd₁₁Pt.

Figure 3 Coordination polyhedra of Sr, Cd, and Pt atoms in the structure of SrCdPt.

3. Database survey

A search of the Pearson's Crystal Data – Crystal Structure Database for Inorganic Compounds (Villars & Cenzual, 2011) for the TiNiSi family of compounds returned 1101 entries with the same prototype. Two ternary compounds of them include strontium and platinum, one compound includes strontium with cadmium, and no compound had formed so far including both cadmium and platinum.

4. Synthesis and crystallization

Starting materials for the synthesis of the title compound were ingots of strontium (99.9+%, Alfa Aesar), cadmium powder (99.9+%, Alfa Aesar) and platinum powder (99.95%, Chempur). A stoichiometric mixture of these elements was weighed and loaded into a tantalum ampoule in an argon-filled dry box. The tantalum ampoule was then weld-sealed under an argon atmosphere and subsequently enclosed in an evacuated silica jacket. The sample was then heated to 1123 K for 15 h, followed by equilibration at 923 K for 4 days, and slow cooling to room temperature. The synthesis procedures were similar to general methods applied in some previous experiments (Gulo et al., 2013).

5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. The highest remaining electron density is located 0.98 Å from the Pt site.

Table 1
Experimental details

Crystal data
Chemical formula	SrCdPt
Mr	395.11
Crystal system, space group	Orthorhombic, Pnma
Temperature (K)	298
a, b, c (Å)	7.5748 (15), 4.4774 (9), 8.6383 (17)
V (Å^3)	292.97 (10)
Z	4
Radiation type	Mo Kα
μ (mm^−1)	72.61
Crystal size (mm)	0.05 × 0.04 × 0.03
Data collection
Diffractometer	Bruker SMART CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
Tmin, Tmax	0.043, 0.113
No. of measured, independent and observed [I > 2σ(I)] reflections	2231, 381, 338
Rint	0.061
(sin θ/λ)max (Å^−1)	0.664
Refinement
R[F^2 > 2σ(F^2)], wR(F^2), S	0.030, 0.066, 1.07
No. of reflections	381
No. of parameters	19
Δρmax, Δρmin (e Å^−3)	2.22, −1.87
Computer programs: SMART and SAINT (Bruker, 2001), SHELXS97 and SHELXL97 (Sheldrick, 2008) and DIAMOND (Brandenburg, 2006).

Supporting information

S1. Chemical context

Exploratory synthesis of polar inter­metallic phases has proven to be productive in terms of novel compositions, new and unprecedented structures, and unusual bonding regimes (Corbett, 2010). Platinum has participated significantly in the formation of ternary inter­metallic compounds. Together with indium, a number of platinum phases have been reported, for example BaPtIn₃ (Palasyuk & Corbett, 2007), SrPtIn (Hoffmann & Pöttgen, 1999), CaPtIn₂ (Hoffmann et al., 1999) or Ca₂Pt₂In (Muts et al., 2007). Some other ternary inter­metallic compounds of platinum with cadmium, viz. Ca₂CdPt₂ (Samal & Corbett, 2012), Ca₆Pt₈Cd₁₆, (Ba/Sr)Cd₄Pt₂ (Samal et al., 2013), Ca₆Cd₁₁Pt (Gulo et al., 2013) and CaCdPt (Kersting et al., 2013) have been isolated recently. They demonstrate the diversity of the structures types adopted. In this communication, we present the crystal structure of SrCdPt.

S2. Structural commentary

SrCdPt crystallizes in the TiNiSi structure type. The titanium, nickel, and silicon sites are occupied by strontium, cadmium, and platinum, respectively, in the structure of the title compound. Although platinum and nickel are in the same group in the periodic table, the platinum in SrCdPt occupies the silicon site and not the nickel site because platinum is the most electronegative metal in this structure, just like silicon in TiNiSi. A count of 56 valence electrons per cell is found in SrCdPt [(Sr:2 + Cd:2 +Pt:10) × 4] whilst TiNiSi contains only 32 valence electrons per cell.

In the compounds of the TiNiSi structure family, the metals listed first in the formula are linked to each other, forming six-membered rings in chair, half-chair, or boat conformations. The adopted conformation is not a function of the electron count, but is due to the nature of the respective metal (Landrum et al., 1998). In the SrCdPt structure, the strontium atoms construct six-membered rings with chair conformations and Sr—Sr distances of 3.870 (2) Å, which is significantly shorter than the sum of the covalent radii of 4.30 Å (Emsley, 1999), indicating strong bonding inter­actions between them (Fig. 1). The existence of such strong Sr—Sr bonds is not noticeable in SrCd₄Pt₂ (Samal et al., 2013). The platinum atoms in the structure of SrCdPt form zigzag chains of edge-sharing cadmium-centred tetra­hedra parallel to the b-axis direction. These chains are condensed via common corners with adjacent chains, building up the three-dimensional network with channels parallel to the b-axis direction in which the Sr atoms reside, as illustrated in Fig. 2.

Strontium has an overall coordination number of 15 and is surrounded by four other strontium, six cadmium, and five platinum atoms. The Sr—Cd distances range from 3.3932 (13) to 3.6124 (17) Å, whereas the Sr—Pt distances vary only slightly, from 3.1943 (11) to 3.2238 (10) Å. Cadmium is located at a site that is surrounded by six strontium and four platinum atoms, whilst platinum has a coordination number of 9 defined by five strontium and four cadmium atoms. The environment of each atom in this structure is represented in Fig. 3. The inter­atomic distances (Sr—Cd, Sr—Pt, and Cd—Pt) are in good agreement with those found in the structures of some other ternary compounds in the alkaline earth–Cd–Pt system (Samal & Corbett, 2012; Samal et al., 2013; Gulo et al., 2013; Kersting et al., 2013). In SrCdPt, the shortest Cd—Cd distance of 3.3197 (15) Å is too long to be considered as a bond. It is significantly longer than the sum of the covalent radii of 2.90 Å (Emsley, 1999). In contrast, cadmium atoms are bonded together, forming Cd₄ tetra­hedra in SrCd₄Pt₂, Cd₈ tetra­hedral stars in Ca₆Cd₁₆Pt₈, and Cd₇ penta­gonal bipyramids in Ca₆Cd₁₁Pt.

S3. Database survey

A search of the Pearson's Crystal Data – Crystal Structure Database for Inorganic Compounds (Villars & Cenzual, 2011) for the TiNiSi family of compounds returned 1101 entries with the same prototype. Two ternary compounds of them include strontium and platinum, one compound includes strontium with cadmium, and no compound had formed so far including both cadmium and platinum.

S4. Synthesis and crystallization

Starting materials for the synthesis of the title compound were ingots of strontium (99.9+%, Alfa Aesar), cadmium powder (99.9+%, Alfa Aesar) and platinum powder (99.95%, Chempur). A stoichiometric mixture of these elements was weighed and loaded into a tantalum ampoule in an argon-filled dry box. The tantalum ampoule was then weld-sealed under an argon atmosphere and subsequently enclosed in an evacuated quartz jacket. The sample was then heated to 1123 K for 15 hours, followed by equilibration at 923 K for 4 days, and slow cooling to room temperature. The synthesis procedures were similar to general methods applied in some previous experiments (Gulo et al., 2013).

S5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. The highest remaining electron density is located 0.98 Å from the Pt site.

Related literature

For related literature, see: Corbett (2010); Emsley (1999); Gulo et al. (2013); Hoffmann & Pöttgen (1999); Hoffmann, Pöttgen, Dronskowski, Landrum, Kuennen & Kotzyba (1999); Kersting et al. (2013); Landrum et al. (1998); Muts et al. (2007); Palasyuk & Corbett (2007); Samal & Corbett (2012); Samal et al. (2013); Villars & Cenzual (2011).

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

Projection of the crystal structure of SrCdPt approximately along [100]. Displacement ellipsoids are represented at the 90% probability level.

View of zigzag chains of cadmium-centred tetrahedra of Pt atoms forming channels along the b-axis direction in the structure of SrCdPt.

Coordination polyhedra of Sr, Cd, and Pt atoms in the structure of SrCdPt.

Strontium cadmium platinum

Crystal data

SrCdPt	F(000) = 656
Mr = 395.11	Dx = 8.958 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 25 reflections
a = 7.5748 (15) Å	θ = 12–18°
b = 4.4774 (9) Å	µ = 72.61 mm^−1
c = 8.6383 (17) Å	T = 298 K
V = 292.97 (10) Å^3	Block, brown
Z = 4	0.05 × 0.04 × 0.03 mm

Data collection

Bruker SMART CCD diffractometer	381 independent reflections
Radiation source: fine-focus sealed tube	338 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.061
Detector resolution: 0 pixels mm^-1	θmax = 28.1°, θmin = 3.6°
ω scans	h = −9→9
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −5→5
Tmin = 0.043, Tmax = 0.113	l = −11→11
2231 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.030	Secondary atom site location: difference Fourier map
wR(F^2) = 0.066	w = 1/[σ^2(Fo^2) + (0.0307P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max < 0.001
381 reflections	Δρmax = 2.22 e Å^−3
19 parameters	Δρmin = −1.87 e Å^−3

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Pt	0.27016 (7)	0.2500	0.37717 (7)	0.0150 (2)
Cd	0.14353 (12)	0.2500	0.06550 (12)	0.0140 (3)
Sr	0.02883 (16)	0.2500	0.68094 (16)	0.0141 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pt	0.0175 (3)	0.0114 (3)	0.0160 (4)	0.000	0.0005 (2)	0.000
Cd	0.0173 (6)	0.0120 (5)	0.0127 (6)	0.000	0.0013 (4)	0.000
Sr	0.0161 (7)	0.0116 (6)	0.0147 (7)	0.000	0.0006 (5)	0.000

Geometric parameters (Å, º)

Pt—Cd^i	2.8435 (8)	Cd—Sr^xi	3.4336 (17)
Pt—Cd^ii	2.8435 (8)	Cd—Sr^v	3.4879 (13)
Pt—Cd	2.8581 (13)	Cd—Sr^iv	3.4879 (13)
Pt—Cd^iii	2.8713 (12)	Cd—Sr^iii	3.6124 (17)
Pt—Sr^iv	3.1943 (11)	Sr—Pt^i	3.1943 (11)
Pt—Sr^v	3.1943 (11)	Sr—Pt^ii	3.1943 (11)
Pt—Sr	3.1980 (15)	Sr—Pt^vi	3.2238 (10)
Pt—Sr^vi	3.2238 (10)	Sr—Pt^vii	3.2238 (10)
Pt—Sr^vii	3.2238 (10)	Sr—Cd^vii	3.3932 (13)
Cd—Pt^iv	2.8435 (8)	Sr—Cd^vi	3.3932 (13)
Cd—Pt^v	2.8435 (8)	Sr—Cd^xii	3.4336 (17)
Cd—Pt^viii	2.8713 (12)	Sr—Cd^i	3.4879 (13)
Cd—Cd^ix	3.3197 (15)	Sr—Cd^ii	3.4879 (13)
Cd—Cd^x	3.3197 (15)	Sr—Cd^viii	3.6124 (17)
Cd—Sr^vii	3.3932 (13)	Sr—Sr^vi	3.870 (2)
Cd—Sr^vi	3.3932 (13)
Cd^i—Pt—Cd^ii	103.87 (4)	Pt^viii—Cd—Sr^iv	130.66 (3)
Cd^i—Pt—Cd	128.03 (2)	Cd^ix—Cd—Sr^iv	97.51 (2)
Cd^ii—Pt—Cd	128.03 (2)	Cd^x—Cd—Sr^iv	175.11 (5)
Cd^i—Pt—Cd^iii	71.03 (3)	Sr^vii—Cd—Sr^iv	120.84 (3)
Cd^ii—Pt—Cd^iii	71.03 (3)	Sr^vi—Cd—Sr^iv	70.47 (2)
Cd—Pt—Cd^iii	119.54 (3)	Sr^xi—Cd—Sr^iv	117.17 (3)
Cd^i—Pt—Sr^iv	138.23 (3)	Sr^v—Cd—Sr^iv	79.86 (4)
Cd^ii—Pt—Sr^iv	69.04 (3)	Pt^iv—Cd—Sr^iii	58.47 (2)
Cd—Pt—Sr^iv	70.13 (3)	Pt^v—Cd—Sr^iii	58.47 (2)
Cd^iii—Pt—Sr^iv	67.79 (3)	Pt—Cd—Sr^iii	106.50 (4)
Cd^i—Pt—Sr^v	69.04 (3)	Pt^viii—Cd—Sr^iii	153.82 (4)
Cd^ii—Pt—Sr^v	138.23 (3)	Cd^ix—Cd—Sr^iii	109.17 (4)
Cd—Pt—Sr^v	70.13 (3)	Cd^x—Cd—Sr^iii	109.17 (4)
Cd^iii—Pt—Sr^v	67.79 (3)	Sr^vii—Cd—Sr^iii	133.73 (2)
Sr^iv—Pt—Sr^v	88.99 (4)	Sr^vi—Cd—Sr^iii	133.73 (2)
Cd^i—Pt—Sr	70.24 (3)	Sr^xi—Cd—Sr^iii	68.55 (3)
Cd^ii—Pt—Sr	70.24 (3)	Sr^v—Cd—Sr^iii	66.02 (3)
Cd—Pt—Sr	125.53 (4)	Sr^iv—Cd—Sr^iii	66.02 (3)
Cd^iii—Pt—Sr	114.93 (4)	Pt^i—Sr—Pt^ii	88.99 (4)
Sr^iv—Pt—Sr	135.06 (2)	Pt^i—Sr—Pt	99.38 (3)
Sr^v—Pt—Sr	135.06 (2)	Pt^ii—Sr—Pt	99.38 (3)
Cd^i—Pt—Sr^vi	142.88 (3)	Pt^i—Sr—Pt^vi	154.71 (5)
Cd^ii—Pt—Sr^vi	72.78 (3)	Pt^ii—Sr—Pt^vi	86.033 (18)
Cd—Pt—Sr^vi	67.51 (3)	Pt—Sr—Pt^vi	105.89 (3)
Cd^iii—Pt—Sr^vi	135.959 (18)	Pt^i—Sr—Pt^vii	86.033 (18)
Sr^iv—Pt—Sr^vi	76.441 (19)	Pt^ii—Sr—Pt^vii	154.71 (5)
Sr^v—Pt—Sr^vi	137.64 (2)	Pt—Sr—Pt^vii	105.89 (3)
Sr—Pt—Sr^vi	74.11 (3)	Pt^vi—Sr—Pt^vii	87.96 (4)
Cd^i—Pt—Sr^vii	72.78 (3)	Pt^i—Sr—Cd^vii	51.57 (2)
Cd^ii—Pt—Sr^vii	142.88 (3)	Pt^ii—Sr—Cd^vii	107.65 (4)
Cd—Pt—Sr^vii	67.51 (3)	Pt—Sr—Cd^vii	138.55 (2)
Cd^iii—Pt—Sr^vii	135.959 (18)	Pt^vi—Sr—Cd^vii	106.76 (4)
Sr^iv—Pt—Sr^vii	137.64 (2)	Pt^vii—Sr—Cd^vii	51.10 (2)
Sr^v—Pt—Sr^vii	76.441 (19)	Pt^i—Sr—Cd^vi	107.65 (4)
Sr—Pt—Sr^vii	74.11 (3)	Pt^ii—Sr—Cd^vi	51.57 (2)
Sr^vi—Pt—Sr^vii	87.96 (4)	Pt—Sr—Cd^vi	138.55 (2)
Pt^iv—Cd—Pt^v	103.87 (4)	Pt^vi—Sr—Cd^vi	51.10 (2)
Pt^iv—Cd—Pt	117.50 (2)	Pt^vii—Sr—Cd^vi	106.76 (4)
Pt^v—Cd—Pt	117.50 (2)	Cd^vii—Sr—Cd^vi	82.56 (4)
Pt^iv—Cd—Pt^viii	108.97 (3)	Pt^i—Sr—Cd^xii	50.65 (2)
Pt^v—Cd—Pt^viii	108.97 (3)	Pt^ii—Sr—Cd^xii	50.65 (2)
Pt—Cd—Pt^viii	99.68 (3)	Pt—Sr—Cd^xii	130.48 (4)
Pt^iv—Cd—Cd^ix	54.88 (2)	Pt^vi—Sr—Cd^xii	109.17 (3)
Pt^v—Cd—Cd^ix	119.11 (5)	Pt^vii—Sr—Cd^xii	109.17 (3)
Pt—Cd—Cd^ix	122.75 (4)	Cd^vii—Sr—Cd^xii	58.19 (3)
Pt^viii—Cd—Cd^ix	54.10 (3)	Cd^vi—Sr—Cd^xii	58.19 (3)
Pt^iv—Cd—Cd^x	119.11 (5)	Pt^i—Sr—Cd^i	50.41 (2)
Pt^v—Cd—Cd^x	54.88 (2)	Pt^ii—Sr—Cd^i	105.21 (4)
Pt—Cd—Cd^x	122.75 (4)	Pt—Sr—Cd^i	50.11 (2)
Pt^viii—Cd—Cd^x	54.10 (3)	Pt^vi—Sr—Cd^i	154.30 (5)
Cd^ix—Cd—Cd^x	84.81 (5)	Pt^vii—Sr—Cd^i	90.55 (2)
Pt^iv—Cd—Sr^vii	167.74 (3)	Cd^vii—Sr—Cd^i	92.00 (2)
Pt^v—Cd—Sr^vii	86.46 (2)	Cd^vi—Sr—Cd^i	151.86 (5)
Pt—Cd—Sr^vii	61.38 (3)	Cd^xii—Sr—Cd^i	95.54 (3)
Pt^viii—Cd—Sr^vii	60.64 (3)	Pt^i—Sr—Cd^ii	105.21 (4)
Cd^ix—Cd—Sr^vii	114.39 (5)	Pt^ii—Sr—Cd^ii	50.41 (2)
Cd^x—Cd—Sr^vii	61.52 (3)	Pt—Sr—Cd^ii	50.11 (2)
Pt^iv—Cd—Sr^vi	86.46 (2)	Pt^vi—Sr—Cd^ii	90.55 (2)
Pt^v—Cd—Sr^vi	167.74 (3)	Pt^vii—Sr—Cd^ii	154.30 (5)
Pt—Cd—Sr^vi	61.38 (3)	Cd^vii—Sr—Cd^ii	151.86 (5)
Pt^viii—Cd—Sr^vi	60.64 (3)	Cd^vi—Sr—Cd^ii	92.00 (2)
Cd^ix—Cd—Sr^vi	61.52 (3)	Cd^xii—Sr—Cd^ii	95.54 (3)
Cd^x—Cd—Sr^vi	114.39 (5)	Cd^i—Sr—Cd^ii	79.86 (4)
Sr^vii—Cd—Sr^vi	82.56 (4)	Pt^i—Sr—Cd^viii	134.25 (2)
Pt^iv—Cd—Sr^xi	60.31 (2)	Pt^ii—Sr—Cd^viii	134.25 (2)
Pt^v—Cd—Sr^xi	60.31 (2)	Pt—Sr—Cd^viii	88.75 (4)
Pt—Cd—Sr^xi	175.05 (4)	Pt^vi—Sr—Cd^viii	48.75 (2)
Pt^viii—Cd—Sr^xi	85.27 (3)	Pt^vii—Sr—Cd^viii	48.75 (2)
Cd^ix—Cd—Sr^xi	60.30 (3)	Cd^vii—Sr—Cd^viii	93.99 (3)
Cd^x—Cd—Sr^xi	60.30 (3)	Cd^vi—Sr—Cd^viii	93.99 (3)
Sr^vii—Cd—Sr^xi	121.81 (3)	Cd^xii—Sr—Cd^viii	140.77 (5)
Sr^vi—Cd—Sr^xi	121.81 (3)	Cd^i—Sr—Cd^viii	113.98 (3)
Pt^iv—Cd—Sr^v	120.35 (4)	Cd^ii—Sr—Cd^viii	113.98 (3)
Pt^v—Cd—Sr^v	59.65 (2)	Pt^i—Sr—Sr^vi	152.61 (6)
Pt—Cd—Sr^v	59.46 (3)	Pt^ii—Sr—Sr^vi	94.42 (2)
Pt^viii—Cd—Sr^v	130.66 (3)	Pt—Sr—Sr^vi	53.25 (3)
Cd^ix—Cd—Sr^v	175.11 (5)	Pt^vi—Sr—Sr^vi	52.64 (2)
Cd^x—Cd—Sr^v	97.51 (2)	Pt^vii—Sr—Sr^vi	101.34 (5)
Sr^vii—Cd—Sr^v	70.47 (2)	Cd^vii—Sr—Sr^vi	149.28 (6)
Sr^vi—Cd—Sr^v	120.84 (3)	Cd^vi—Sr—Sr^vi	95.53 (3)
Sr^xi—Cd—Sr^v	117.17 (3)	Cd^xii—Sr—Sr^vi	144.11 (3)
Pt^iv—Cd—Sr^iv	59.65 (2)	Cd^i—Sr—Sr^vi	102.75 (5)
Pt^v—Cd—Sr^iv	120.35 (4)	Cd^ii—Sr—Sr^vi	58.53 (3)
Pt—Cd—Sr^iv	59.46 (3)	Cd^viii—Sr—Sr^vi	55.44 (3)

Symmetry codes: (i) −x+1/2, −y+1, z+1/2; (ii) −x+1/2, −y, z+1/2; (iii) x+1/2, y, −z+1/2; (iv) −x+1/2, −y, z−1/2; (v) −x+1/2, −y+1, z−1/2; (vi) −x, −y, −z+1; (vii) −x, −y+1, −z+1; (viii) x−1/2, y, −z+1/2; (ix) −x, −y, −z; (x) −x, −y+1, −z; (xi) x, y, z−1; (xii) x, y, z+1.