Crystal structure and electrical resistance property of Rb_0.21(H₂O)_yWS₂

Rb_0.21(H₂O)_yWS₂, rubidium hydrate di­thio­tungstate, is a new quasi two-dimensional sulfide. Its crystal structure consists of ordered WS₂ layers, separated by disordered Rb⁺ ions and water mol­ecules. All atomic sites are located on mirror planes. The WS₂ layers are composed of edge-sharing [WS₆] octa­hedra and extend parallel to (001). The presence of structural water was revealed by thermogravimetry, but the position and exact amount could not be determined in the present study. The temperature dependence of the electrical resistance indicates that Rb_0.21(H₂O)_yWS₂ is semiconducting between 80–300 K.

1. Chemical context

Typical two-dimensional structures of MS₂ compounds (M = transition metals of group IVB–VIB) facilitate the inter­calation of various atoms, ions or organic mol­ecules (Whittingham et al., 1978). For example, A_xMS₂ (A = alkali metal; M = Nb, Ta, Ti, V) compounds can be prepared in high-temperature solid-state reactions (800–1000 K). These com­pounds can react with water mol­ecules to form ionic hydrates A⁺_x(H₂O)_y[MS₂]^x− (Omloo & Jellinek, 1970; Lerf & Schöllhorn, 1977; Lobert et al., 1992) that exhibit ion-exchange and solvent-exchange capacities. Some of the A⁺_x(H₂O)_y[MS₂]^x− compounds show unusual superconducting properties (Schöllhorn & Weiss, 1974; Sernetz et al., 1974). Recently, by removing alkali ions from inter­calated A⁺_x(H₂O)_y[MS₂]^x− (A = alkali metal) compounds, several metastable MS₂ (M = Mo, W) phases with new crystal structures and novel physical properties were reported (Fang et al., 2018, 2019). In order to identify the formation mechanism of metastable MS₂ from A⁺_x(H₂O)_y[MS₂]^x−, it is necessary to uncover the role of alkali ions inter­calated into the inter­layers of MS₂.

In this communication, we report the preparation of Rb_0.21(H₂O)_yWS₂, its crystal structure determination by single crystal X-ray diffraction, its thermal behaviour and its electrical resistance property.

2. Structural commentary

Rb_0.21(H₂O)_yWS₂ crystallizes in the monoclinic P2₁/m (No. 11) space group. The structure consists of one independent W site, two independent S sites and two independent Rb sites, all of them located on a mirror plane (Wyckoff position 2e). The crystal structure features ordered WS₂ layers separated by disordered Rb⁺ ions, and of water mol­ecules. The latter could not be localized in the current study, hence y in Rb_0.21(H₂O)_yWS₂ remains undetermined (see Experimental, and discussion below). Compared with [WS₆]^8– trigonal prisms in 2H-WS₂ (Schutte et al., 1987), the WS₂ layer in Rb_0.21(H₂O)_yWS₂ is composed of edge-sharing [WS₆]^8.21– octa­hedra. The W—S bond lengths range from 2.403 (4) Å to 2.550 (5) Å, and thus the average W—S distance is larger than that in 2H-WS₂ [2.405 (5) Å; Schutte et al., 1987]. The WS₂ layers extend parallel to (001) (Fig. 1). The shortest W—W bond length of 2.7678 (15) Å is between pairs of W atoms aligned in the [10] direction, much shorter than the W⋯W distance of 3.2524 (18) Å along [010]. Similar metal–metal separations also exist in some metastable MS₂ phases prepared by de-inter­calating alkali ions from A_x(H₂O)_yMS₂ compounds (Yu et al., 2018; Shang et al., 2018). The Rb⁺ cations show a one-sided coordination to the S atoms of the adjacent layer. The Rb—S bonds range from 3.47 (7) Å to 3.64 (5) Å, comparable to the Rb—S bonds [3.344 (7)–3.561 (1) Å] in RbCr₅S₈ (Huster, 1978).

Figure 1 Crystal structure of Rb0.21(H2O)yWS2 with displacement ellipsoids drawn at the 30% probability level.

Similar to K_x(H₂O)_yTaS₂ and K_x(H₂O)_yNbS₂ (Graf et al., 1977), it was impossible to determine the light O atoms of water mol­ecules in the title compound from X-ray diffraction data at room temperature, as a result of diffuse electron density in the inter­layer space. However, we could localize the positions of disordered Rb⁺ ions with large displacement parameters. Stacking disorder of the layers is common for layered dichalcogenides, which may contribute to the diffuse electron density. Large displacement parameters of exchangeable cations and water mol­ecules were also reported for A_x(H₂O)_yTaS₂ and A_x(H₂O)_yNbS₂ (A = alkali metal) compounds (Röder et al., 1979; Wein et al. 1986; Lobert et al., 1992).

3. Electrical resistance property

The electrical resistance of Rb_0.21(H₂O)_yWS₂ increases with the decrease of temperature (80–300 K) (Fig. 2), which is characteristic of a semiconductor.

Figure 2 Temperature-dependence of the log(Resistance) for Rb0.21(H2O)yWS2.

4. Synthesis and crystallization

A rubidium di­thio­tungstate Rb_xWS₂ was synthesized in a solid-state reaction. The starting Rb₂S₂ powder was prepared in a reaction of stoichiometric amounts of Rb pieces and S powder in liquid NH₃. The obtained Rb₂S₂ powder, W powder and S powder were mixed in the molar ratio of 1:1:1 in a glove box filled with Ar. The mixture was ground carefully and loaded in a carbon-coated fused-silica tube. The tube was sealed under a 10⁻⁴ Torr atmosphere and slowly heated to 1123 K at 5 K min⁻¹. After three days, the furnace was cooled down naturally to room temperature. Subsequent removal of the extra flux by washing with distilled water led to the isolation of crystals of Rb_0.21(H₂O)_yWS₂. The morphology and element composition were investigated by using an EDXS-equipped Hitachi S-4800 scanning electronic microscope. In addition, the Rb/W ratio in the Rb_x(H₂O)_yWS₂ crystals was determined by ICP-OES. The SEM image and EDX spectrum of Rb_0.21(H₂O)_yWS₂ crystals are shown in Fig. 3. The ratio of Rb/W from the EDXS analysis is close to 0.21, which is consistent with the the diffraction data and results from ICP–OES measurements (Table 1). The experimental powder X-ray diffraction (PXRD) pattern matches well with the simulated one (Fig. 4) by using the Rietveld refinement method (Rodríguez-Carvajal, 1993; R_p = 9.9%, R_wp = 12.6% and χ² = 1.3). In the TG–DTA analyses (Fig. 5), one obvious endothermic effect and concomitant mass loss were observed at 343 K, which is associated with water evaporation. In order to judge whether water mol­ecules are surface-adsorbed water or structural water, the Rb_0.21(H₂O)_yWS₂ crystals were heated up to 373 K for further PXRD measurement. The sample was prepared in an Ar-protected glove box and sealed with vacuum tape. The (002) reflection clearly moved to higher diffraction angles, indicating the shrinkage of the unit cell due to loss of inter­calated water (Fig. 6). However, it was impossible to accurately determine the water content by mass loss alone because of the inter­ference of possible surface-adsorbed water.

Table 1
Results of ICP–OES measurement of Rb_0.21(H₂O)_yWS₂

Element	Weight (%)	atom (%)
W	67.6	36.77
Rb	6.6	7.72

Figure 3 SEM image and EDXS spectrum of Rb0.21(H2O)yWS2.

Figure 4 Rietveld plot of Rb0.21(H2O)yWS2.

Figure 5 TG–DTA analysis of Rb0.21(H2O)yWS2.

Figure 6 Power X-ray diffraction pattern of Rb0.21(H2O)yWS2 and Rb0.21WS2.

5. Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 2. The localization of ordered W and S sites of the WS₂ layers was unproblematic. The highest inter­layer difference electron density peak was then treated as a single but partially occupied Rb site. No evidence of superstructure reflections in reciprocal space was found for the ordering of the Rb site. Then, the W, S sites and the underoccupied Rb site were refined with anisotropic displacement parameters. Because of very large anisotropic displacement parameters (U¹¹ = 0.59 Ų) of the Rb site, splitting of this site was considered, resulting in a residual R₁ = 0.051. Modelling the O sites as being part of this disorder, or of remaining electron density peaks in the vicinity of the Rb sites was not successful, and therefore we did not include the apparently disordered water mol­ecules in the final structure model. The remaining maximum and minimum electron densities are located 0.87 and 1.14 Å, respectively, from the W1 site.

Table 2
Experimental details

Crystal data
Chemical formula	Rb0.21(H2O)yWS2
Mr	277.23
Crystal system, space group	Monoclinic, P21/m
Temperature (K)	298
a, b, c (Å)	5.703 (3), 3.2524 (18), 9.423 (5)
β (°)	99.724 (16)
V (Å^3)	172.27 (16)
Z	2
Radiation type	Mo Kα
μ (mm^−1)	39.25
Crystal size (mm)	0.05 × 0.03 × 0.01
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2015)
Tmin, Tmax	0.251, 0.674
No. of measured, independent and observed [I > 2σ(I)] reflections	1167, 352, 327
Rint	0.030
(sin θ/λ)max (Å^−1)	0.593
Refinement
R[F^2 > 2σ(F^2)], wR(F^2), S	0.050, 0.124, 1.10
No. of reflections	352
No. of parameters	33
H-atom treatment	H-atom parameters not defined
Δρmax, Δρmin (e Å^−3)	2.45, −1.66
Computer programs: APEX3 and SAINT (Bruker, 2015), SHELXS (Sheldrick, 2008), SHELXL2014/7 (Sheldrick, 2015), DIAMOND (Brandenburg, 2004) and publCIF (Westrip, 2010).

Supporting information

Computing details

Data collection: APEX3 (Bruker, 2015); cell refinement: SAINT (Bruker, 2015); data reduction: SAINT (Bruker, 2015); program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg, 2004); software used to prepare material for publication: publCIF (Westrip, 2010).

rubidium hydrate dithiotungstate

Crystal data

Rb0.21(H2O)yWS2	F(000) = 237
Mr = 277.23	Dx = 5.345 Mg m^−3
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
a = 5.703 (3) Å	Cell parameters from 68 reflections
b = 3.2524 (18) Å	θ = 3.9–23.0°
c = 9.423 (5) Å	µ = 39.25 mm^−1
β = 99.724 (16)°	T = 298 K
V = 172.27 (16) Å^3	Plate, black
Z = 2	0.05 × 0.03 × 0.01 mm

Data collection

Bruker APEXII CCD diffractometer	327 reflections with I > 2σ(I)
phi and ω scans	Rint = 0.030
Absorption correction: multi-scan (SADABS; Bruker, 2015)	θmax = 24.9°, θmin = 2.2°
Tmin = 0.251, Tmax = 0.674	h = −6→6
1167 measured reflections	k = −3→3
352 independent reflections	l = −11→10

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H-atom parameters not defined
R[F^2 > 2σ(F^2)] = 0.050	w = 1/[σ^2(Fo^2) + (0.1024P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.124	(Δ/σ)max < 0.001
S = 1.10	Δρmax = 2.45 e Å^−3
352 reflections	Δρmin = −1.66 e Å^−3
33 parameters

Special details

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.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
W1	0.19782 (11)	0.7500	1.00615 (8)	0.0371 (5)
S2	0.3744 (9)	0.2500	0.8600 (6)	0.0376 (12)
S3	0.1409 (10)	0.2500	1.1850 (6)	0.0401 (12)
Rb4	0.21 (4)	−0.2500	0.534 (6)	0.14 (6)	0.14 (7)
Rb5	0.38 (2)	−0.2500	0.525 (8)	0.17 (2)	0.20 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
W1	0.0319 (7)	0.0374 (7)	0.0423 (7)	0.000	0.0073 (4)	0.000
S2	0.034 (2)	0.038 (3)	0.041 (3)	0.000	0.007 (2)	0.000
S3	0.041 (3)	0.039 (3)	0.041 (3)	0.000	0.008 (2)	0.000
Rb4	0.28 (14)	0.12 (4)	0.04 (2)	0.000	0.06 (4)	0.000
Rb5	0.18 (6)	0.24 (6)	0.08 (3)	0.000	0.01 (3)	0.000

Geometric parameters (Å, º)

W1—S3^i	2.403 (4)	Rb4—Rb5	0.99 (10)
W1—S3	2.403 (4)	Rb4—Rb4^x	2.9 (3)
W1—S3^ii	2.408 (5)	Rb4—Rb4^xi	2.9 (3)
W1—S2	2.454 (4)	Rb4—Rb5^xii	3.0 (3)
W1—S2^i	2.454 (4)	Rb4—Rb5^xiii	3.0 (3)
W1—S2^iii	2.550 (5)	Rb4—Rb4^i	3.252 (2)
W1—W1^ii	2.7678 (15)	Rb4—Rb4^v	3.2524 (19)
W1—W1^iv	2.7678 (15)	Rb4—Rb5^i	3.40 (3)
S2—W1^v	2.454 (4)	Rb4—Rb5^v	3.40 (3)
S2—W1^iii	2.550 (5)	Rb4—S2^v	3.47 (7)
S2—Rb4	3.47 (7)	Rb4—S3^vii	3.58 (11)
S2—Rb4^i	3.47 (7)	Rb5—Rb5^xii	2.23 (19)
S2—Rb5^i	3.56 (8)	Rb5—Rb5^xiii	2.23 (19)
S2—Rb5	3.56 (8)	Rb5—Rb4^xii	3.0 (3)
S3—W1^v	2.403 (4)	Rb5—Rb4^xiii	3.0 (3)
S3—W1^ii	2.408 (5)	Rb5—Rb5^i	3.2524 (18)
S3—Rb5^vi	3.53 (6)	Rb5—Rb5^v	3.2524 (18)
S3—Rb4^vii	3.58 (11)	Rb5—Rb4^v	3.40 (3)
S3—Rb4^viii	3.63 (4)	Rb5—Rb4^i	3.40 (3)
S3—Rb4^ix	3.63 (4)	Rb5—S3^vi	3.53 (6)
S3—Rb5^viii	3.64 (5)	Rb5—S2^v	3.56 (8)
S3—Rb5^ix	3.64 (5)
S3^i—W1—S3	85.18 (18)	Rb5^xii—Rb4—Rb5^i	40 (3)
S3^i—W1—S3^ii	109.76 (14)	Rb5^xiii—Rb4—Rb5^i	106 (4)
S3—W1—S3^ii	109.76 (14)	Rb4^i—Rb4—Rb5^i	16.9 (16)
S3^i—W1—S2	163.5 (2)	Rb4^v—Rb4—Rb5^i	163.1 (16)
S3—W1—S2	93.55 (13)	Rb5—Rb4—Rb5^v	73.1 (16)
S3^ii—W1—S2	86.20 (17)	Rb4^x—Rb4—Rb5^v	71 (3)
S3^i—W1—S2^i	93.55 (13)	Rb4^xi—Rb4—Rb5^v	140 (7)
S3—W1—S2^i	163.5 (2)	Rb5^xii—Rb4—Rb5^v	106 (4)
S3^ii—W1—S2^i	86.20 (17)	Rb5^xiii—Rb4—Rb5^v	40 (3)
S2—W1—S2^i	82.99 (18)	Rb4^i—Rb4—Rb5^v	163.1 (16)
S3^i—W1—S2^iii	83.36 (18)	Rb4^v—Rb4—Rb5^v	16.9 (16)
S3—W1—S2^iii	83.36 (18)	Rb5^i—Rb4—Rb5^v	146 (3)
S3^ii—W1—S2^iii	161.7 (2)	Rb5—Rb4—S2^v	87 (10)
S2—W1—S2^iii	80.13 (16)	Rb4^x—Rb4—S2^v	91.3 (12)
S2^i—W1—S2^iii	80.13 (16)	Rb4^xi—Rb4—S2^v	124 (4)
S3^i—W1—W1^ii	102.78 (13)	Rb5^xii—Rb4—S2^v	108 (5)
S3—W1—W1^ii	54.97 (13)	Rb5^xiii—Rb4—S2^v	79 (2)
S3^ii—W1—W1^ii	54.79 (10)	Rb4^i—Rb4—S2^v	118.0 (6)
S2—W1—W1^ii	89.78 (11)	Rb4^v—Rb4—S2^v	62.0 (6)
S2^i—W1—W1^ii	140.78 (13)	Rb5^i—Rb4—S2^v	116 (4)
S2^iii—W1—W1^ii	136.53 (8)	Rb5^v—Rb4—S2^v	62 (2)
S3^i—W1—W1^iv	54.97 (13)	Rb5—Rb4—S2	87 (10)
S3—W1—W1^iv	102.78 (13)	Rb4^x—Rb4—S2	124 (4)
S3^ii—W1—W1^iv	54.79 (10)	Rb4^xi—Rb4—S2	91.3 (12)
S2—W1—W1^iv	140.78 (13)	Rb5^xii—Rb4—S2	79 (2)
S2^i—W1—W1^iv	89.78 (11)	Rb5^xiii—Rb4—S2	108 (5)
S2^iii—W1—W1^iv	136.53 (8)	Rb4^i—Rb4—S2	62.0 (6)
W1^ii—W1—W1^iv	71.96 (5)	Rb4^v—Rb4—S2	118.0 (6)
W1^v—S2—W1	82.99 (18)	Rb5^i—Rb4—S2	62 (2)
W1^v—S2—W1^iii	99.87 (16)	Rb5^v—Rb4—S2	116 (4)
W1—S2—W1^iii	99.87 (16)	S2^v—Rb4—S2	56.0 (12)
W1^v—S2—Rb4	96.3 (15)	Rb5—Rb4—S3^vii	138 (10)
W1—S2—Rb4	137 (3)	Rb4^x—Rb4—S3^vii	68 (4)
W1^iii—S2—Rb4	122 (3)	Rb4^xi—Rb4—S3^vii	68 (4)
W1^v—S2—Rb4^i	137 (3)	Rb5^xii—Rb4—S3^vii	133.8 (12)
W1—S2—Rb4^i	96.3 (15)	Rb5^xiii—Rb4—S3^vii	133.8 (12)
W1^iii—S2—Rb4^i	122 (3)	Rb4^i—Rb4—S3^vii	90.000 (2)
Rb4—S2—Rb4^i	56.0 (12)	Rb4^v—Rb4—S3^vii	90.000 (1)
W1^v—S2—Rb5^i	150.1 (12)	Rb5^i—Rb4—S3^vii	102.5 (13)
W1—S2—Rb5^i	105.1 (13)	Rb5^v—Rb4—S3^vii	102.5 (12)
W1^iii—S2—Rb5^i	106.8 (18)	S2^v—Rb4—S3^vii	56.3 (7)
Rb4—S2—Rb5^i	57.9 (7)	S2—Rb4—S3^vii	56.3 (7)
Rb4^i—S2—Rb5^i	16.1 (18)	Rb4—Rb5—Rb5^xii	132 (4)
W1^v—S2—Rb5	105.1 (13)	Rb4—Rb5—Rb5^xiii	132 (4)
W1—S2—Rb5	150.1 (12)	Rb5^xii—Rb5—Rb5^xiii	94 (10)
W1^iii—S2—Rb5	106.8 (18)	Rb4—Rb5—Rb4^xii	146 (2)
Rb4—S2—Rb5	16.1 (18)	Rb5^xii—Rb5—Rb4^xii	14.3 (18)
Rb4^i—S2—Rb5	57.9 (7)	Rb5^xiii—Rb5—Rb4^xii	80 (8)
Rb5^i—S2—Rb5	54.4 (14)	Rb4—Rb5—Rb4^xiii	146 (2)
W1^v—S3—W1	85.18 (18)	Rb5^xii—Rb5—Rb4^xiii	80 (8)
W1^v—S3—W1^ii	70.24 (14)	Rb5^xiii—Rb5—Rb4^xiii	14.3 (18)
W1—S3—W1^ii	70.24 (14)	Rb4^xii—Rb5—Rb4^xiii	66 (7)
W1^v—S3—Rb5^vi	111.4 (15)	Rb4—Rb5—Rb5^i	90.00 (5)
W1—S3—Rb5^vi	111.4 (16)	Rb5^xii—Rb5—Rb5^i	43 (5)
W1^ii—S3—Rb5^vi	178 (2)	Rb5^xiii—Rb5—Rb5^i	137 (5)
W1^v—S3—Rb4^vii	132.7 (12)	Rb4^xii—Rb5—Rb5^i	57 (3)
W1—S3—Rb4^vii	132.7 (11)	Rb4^xiii—Rb5—Rb5^i	123 (3)
W1^ii—S3—Rb4^vii	94 (3)	Rb4—Rb5—Rb5^v	90.00 (10)
Rb5^vi—S3—Rb4^vii	83.2 (13)	Rb5^xii—Rb5—Rb5^v	137 (5)
W1^v—S3—Rb4^viii	159 (2)	Rb5^xiii—Rb5—Rb5^v	43 (5)
W1—S3—Rb4^viii	109.0 (6)	Rb4^xii—Rb5—Rb5^v	123 (3)
W1^ii—S3—Rb4^viii	129 (3)	Rb4^xiii—Rb5—Rb5^v	57 (3)
Rb5^vi—S3—Rb4^viii	49 (5)	Rb5^i—Rb5—Rb5^v	180.00 (7)
Rb4^vii—S3—Rb4^viii	47 (5)	Rb4—Rb5—Rb4^v	73.1 (17)
W1^v—S3—Rb4^ix	109.0 (6)	Rb5^xii—Rb5—Rb4^v	153 (5)
W1—S3—Rb4^ix	159 (2)	Rb5^xiii—Rb5—Rb4^v	60 (6)
W1^ii—S3—Rb4^ix	129 (3)	Rb4^xii—Rb5—Rb4^v	140 (3)
Rb5^vi—S3—Rb4^ix	49 (5)	Rb4^xiii—Rb5—Rb4^v	74 (4)
Rb4^vii—S3—Rb4^ix	47 (5)	Rb5^i—Rb5—Rb4^v	163.1 (16)
Rb4^viii—S3—Rb4^ix	53.3 (7)	Rb5^v—Rb5—Rb4^v	16.9 (16)
W1^v—S3—Rb5^viii	147.5 (16)	Rb4—Rb5—Rb4^i	73.1 (16)
W1—S3—Rb5^viii	103.9 (12)	Rb5^xii—Rb5—Rb4^i	60 (6)
W1^ii—S3—Rb5^viii	142.2 (16)	Rb5^xiii—Rb5—Rb4^i	153 (5)
Rb5^vi—S3—Rb5^viii	36 (3)	Rb4^xii—Rb5—Rb4^i	74 (4)
Rb4^vii—S3—Rb5^viii	61 (4)	Rb4^xiii—Rb5—Rb4^i	140 (3)
Rb4^viii—S3—Rb5^viii	15.7 (16)	Rb5^i—Rb5—Rb4^i	16.9 (16)
Rb4^ix—S3—Rb5^viii	55.8 (6)	Rb5^v—Rb5—Rb4^i	163.1 (16)
W1^v—S3—Rb5^ix	103.9 (12)	Rb4^v—Rb5—Rb4^i	146 (3)
W1—S3—Rb5^ix	147.5 (16)	Rb4—Rb5—S3^vi	125 (9)
W1^ii—S3—Rb5^ix	142.2 (16)	Rb5^xii—Rb5—S3^vi	75 (3)
Rb5^vi—S3—Rb5^ix	36 (3)	Rb5^xiii—Rb5—S3^vi	75 (3)
Rb4^vii—S3—Rb5^ix	61 (4)	Rb4^xii—Rb5—S3^vi	67 (4)
Rb4^viii—S3—Rb5^ix	55.8 (6)	Rb4^xiii—Rb5—S3^vi	67 (4)
Rb4^ix—S3—Rb5^ix	15.7 (16)	Rb5^i—Rb5—S3^vi	90.000 (5)
Rb5^viii—S3—Rb5^ix	53.0 (8)	Rb5^v—Rb5—S3^vi	90.000 (2)
Rb5—Rb4—Rb4^x	141 (2)	Rb4^v—Rb5—S3^vi	100 (3)
Rb5—Rb4—Rb4^xi	141 (2)	Rb4^i—Rb5—S3^vi	100 (3)
Rb4^x—Rb4—Rb4^xi	69 (9)	Rb4—Rb5—S2^v	77 (8)
Rb5—Rb4—Rb5^xii	34 (2)	Rb5^xii—Rb5—S2^v	128 (3)
Rb4^x—Rb4—Rb5^xii	157 (2)	Rb5^xiii—Rb5—S2^v	87 (3)
Rb4^xi—Rb4—Rb5^xii	107.5 (14)	Rb4^xii—Rb5—S2^v	123 (3)
Rb5—Rb4—Rb5^xiii	34 (2)	Rb4^xiii—Rb5—S2^v	92.3 (10)
Rb4^x—Rb4—Rb5^xiii	107.5 (13)	Rb5^i—Rb5—S2^v	117.2 (7)
Rb4^xi—Rb4—Rb5^xiii	157 (2)	Rb5^v—Rb5—S2^v	62.8 (7)
Rb5^xii—Rb4—Rb5^xiii	66 (7)	Rb4^v—Rb5—S2^v	59.7 (19)
Rb5—Rb4—Rb4^i	90.00 (5)	Rb4^i—Rb5—S2^v	112 (3)
Rb4^x—Rb4—Rb4^i	125 (5)	S3^vi—Rb5—S2^v	55.4 (8)
Rb4^xi—Rb4—Rb4^i	55 (5)	Rb4—Rb5—S2	77 (8)
Rb5^xii—Rb4—Rb4^i	57 (3)	Rb5^xii—Rb5—S2	87 (3)
Rb5^xiii—Rb4—Rb4^i	123 (3)	Rb5^xiii—Rb5—S2	128 (3)
Rb5—Rb4—Rb4^v	90.000 (19)	Rb4^xii—Rb5—S2	92.3 (10)
Rb4^x—Rb4—Rb4^v	55 (5)	Rb4^xiii—Rb5—S2	123 (3)
Rb4^xi—Rb4—Rb4^v	125 (5)	Rb5^i—Rb5—S2	62.8 (7)
Rb5^xii—Rb4—Rb4^v	123 (3)	Rb5^v—Rb5—S2	117.2 (7)
Rb5^xiii—Rb4—Rb4^v	57 (3)	Rb4^v—Rb5—S2	112 (3)
Rb4^i—Rb4—Rb4^v	180.00 (10)	Rb4^i—Rb5—S2	59.7 (19)
Rb5—Rb4—Rb5^i	73.1 (16)	S3^vi—Rb5—S2	55.4 (8)
Rb4^x—Rb4—Rb5^i	140 (7)	S2^v—Rb5—S2	54.4 (14)
Rb4^xi—Rb4—Rb5^i	71 (3)

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