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ISSN: 2056-9890

Crystal structure of trirubidium citrate from laboratory X-ray powder diffraction data and DFT comparison

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aAtlantic International University, Honolulu HI, USA, and bIllinois Institute of Technology, Chicago IL, USA
*Correspondence e-mail: kaduk@polycrystallography.com

Edited by A. Van der Lee, Université de Montpellier II, France (Received 31 December 2016; accepted 21 January 2017; online 27 January 2017)

The crystal structure of trirubidium citrate, 3Rb+·C6H5O73−, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The two independent Rb+ cations are seven- and eight-coordinate, with bond-valence sums of 0.99 and 0.92 valence units. The coordination polyhedra share edges and corners to form a three-dimensional framework. The only hydrogen bond is an intra­molecular one between the hy­droxy group and the central carboxyl­ate, with graph set S(5). The hydro­phobic methyl­ene groups lie in pockets in the framework.

1. Chemical context

In the course of a systematic study of the crystal structures of Group 1 (alkali metal) citrate salts to understand the anion's conformational flexibility, ionization, coordination tendencies, and hydrogen bonding, we have determined several new crystal structures. Most of the new structures were solved using X-ray powder diffraction data (laboratory and/or synchrotron), but single crystals were used where available. The general trends and conclusions about the sixteen new compounds and twelve previously characterized structures are being reported separately (Rammohan & Kaduk, 2017a[Rammohan, A. & Kaduk, J. A. (2017a). Acta Cryst. B73. Submitted.]). Eight of the new structures – NaKHC6H5O7, NaK2C6H5O7, Na3C6H5O7, NaH2C6H5O7, Na2HC6H5O7, K3C6H5O7, Rb2HC6H5O7, and Rb3C6H5O7(H2O) – have been published recently (Rammohan & Kaduk, 2016a[Rammohan, A. & Kaduk, J. A. (2016a). Acta Cryst. E72, 170-173.],b[Rammohan, A. & Kaduk, J. A. (2016b). Acta Cryst. E72, 403-406.],c[Rammohan, A. & Kaduk, J. A. (2016c). Acta Cryst. E72, 793-796.],d[Rammohan, A. & Kaduk, J. A. (2016d). Acta Cryst. E72, 854-857.],e[Rammohan, A. & Kaduk, J. A. (2016e). Acta Cryst. E72, 1159-1162.], 2017b[Rammohan, A. & Kaduk, J. A. (2017b). Acta Cryst. E73, 92-95.],c[Rammohan, A. & Kaduk, J. A. (2017c). Acta Cryst. E73, 286-290.]; Rammohan et al., 2016[Rammohan, A., Sarjeant, A. A. & Kaduk, J. A. (2016). Acta Cryst. E72, 943-946.]), and two additional structures – KH2C6H5O7 and KH2C6H5O7(H2O)2 – have been communicated to the CSD (Kaduk & Stern, 2016a[Kaduk, J. A. & Stern, C. (2016a). CSD Communication 1446457-1446458. CCDC, Cambridge, England.],b[Kaduk, J. A. & Stern, C. (2016b). CSD Communication 1446460-1446461. CCDC, Cambridge, England.]).

[Scheme 1]

2. Structural commentary

The asymmetric unit of the title compound is shown in Fig. 1[link]. The root-mean-square deviation of the non-hydrogen atoms in the Rietveld-refined and DFT-optimized structures is 0.052 Å (Fig. 2[link]). The largest difference is 0.086 Å, at C1. The excellent agreement between the two structures is strong evidence that the experimental structure is correct (van de Streek & Neumann, 2014[Streek, J. van de & Neumann, M. A. (2014). Acta Cryst. B70, 1020-1032.]). This discussion uses the DFT-optimized structure. Most of the bond lengths, bond angles, and torsion angles fall within the normal ranges indicated by a Mercury Mogul geometry check (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]). The C3—C2—C1 angle of 116.5° is flagged as unusual [Z-score = 2.3; average = 112.7 (16)°]. The C2—C3—C2 angle of 106.0° is also flagged as unusual [Z-score = 2.5; average = 109.6 (14)°]. This hygroscopic compound was measured in situ, so perhaps slightly unusual geometry could be expected.

[Figure 1]
Figure 1
The asymmetric unit of trirubidium citrate, showing the atom numbering. The atoms are represented by 50% probability spheroids.
[Figure 2]
Figure 2
Comparison of the refined and optimized structures of trirubidium citrate. The refined structure is in red, and the DFT-optimized structure is in blue.

The citrate anion occurs in the trans,trans-conformation, which is one of the two low-energy conformations of an isolated citrate. The central carboxyl­ate group and the hy­droxy group lie on a mirror plane. The terminal carboxyl­ate O11 atom and the central carboxyl­ate O15 atom chelate to Rb19, O11 and the central carboxyl­ate O16 atom chelate to a second Rb19, and the terminal carboxyl­ate O12 atom and the O17 hy­droxy group chelate to a third Rb19. The terminal O11–C1–C12 carboxyl­ate group acts as a bidentate ligand to Rb20. The Mulliken overlap populations and atomic charges indicate that the metal-oxygen bonding is ionic.

The Bravais–Friedel–Donnay–Harker (Bravais, 1866[Bravais, A. (1866). In Études Cristallographiques. Paris: Gauthier Villars.]; Friedel, 1907[Friedel, G. (1907). Bull. Soc. Fr. Mineral. 30, 326-455.]; Donnay & Harker, 1937[Donnay, J. D. H. & Harker, D. (1937). Am. Mineral. 22, 446-467.]) morphology suggests that we might expect blocky morphology for trirubidium citrate, with {011} as the principal faces. A 4th-order spherical harmonic texture model was included in the refinement. The texture index was 1.001, indicating that preferred orientation was not significant for this rotated flat-plate specimen.

3. Supra­molecular features

The two independent Rb+ cations, Rb19 and Rb20, are seven- and eight-coordinate, with bond-valence sums of 0.99 and 0.92 valence units, respectively. The coordination polyhedra share edges and corners to form a three-dimensional network (Fig. 3[link]). The only hydrogen bond is an intra­molecular one (Table 1[link]) between the hy­droxy group and the central carboxyl­ate, with graph set S(5). The Mulliken overlap population indicates, by the correlation in Rammohan & Kaduk (2017a[Rammohan, A. & Kaduk, J. A. (2017a). Acta Cryst. B73. Submitted.]), that this hydrogen bond contributes 12.6 kcal mol−1 to the crystal energy.

Table 1
Hydrogen-bond geometry (Å, °) for ramm077c_DFT[link]

D—H⋯A D—H H⋯A DA D—H⋯A
O17—H18⋯O16 0.981 1.862 2.572 126.7
[Figure 3]
Figure 3
Crystal structure of trirubidium citrate, viewed down the b axis.

4. Database survey

Details of the comprehensive literature search for citrate structures are presented in Rammohan & Kaduk (2017a[Rammohan, A. & Kaduk, J. A. (2017a). Acta Cryst. B73. Submitted.]). A reduced cell search of the cell of trirubidium citrate monohydrate in the Cambridge Structural Database (Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) (increasing the default tolerance from 1.5 to 2.0%) yielded 221 hits, but combining the cell search with the elements C, H, O, and Rb only yielded no hits.

5. Synthesis and crystallization

A portion of Rb3(C6H5O7)(H2O)1 (Rammohan & Kaduk, 2017c[Rammohan, A. & Kaduk, J. A. (2017c). Acta Cryst. E73, 286-290.]) was heated at 14 K min−1 to 463 K and held at that temperature for 10 min. The white solid was immediately transferred to a glass vial to cool.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. Diffraction data are displayed in Fig. 4[link]. The white solid was ground in a mortar and pestle, blended with NIST 640b Si inter­nal standard in order to verify the calibrated goniometer zero error, packed into a standard Bruker D2 sample cell and protected from the atmosphere by an 8 µm thick Kapton window attached to the cell with Vaseline. The powder pattern indicated that the sample was still hydrated, so the blend was re-heated at 17 K min−1 to 483 (10) K and held for 10 min. Re-measuring the powder pattern indicated that a new phase had formed.

Table 2
Experimental details

Crystal data
Chemical formula 3Rb+·C6H5O73−
Mr 445.50
Crystal system, space group Orthorhombic, Pnma
Temperature (K) 300
a, b, c (Å) 7.9096 (2), 10.7733 (3), 12.6986 (3)
V3) 1082.08 (7)
Z 4
Radiation type Kα1, Kα2, λ = 1.540593, 1.544451 Å
Specimen shape, size (mm) Flat sheet, 24 × 24
 
Data collection
Diffractometer Bruker D2 Phaser
Specimen mounting Standard PMMA holder with Kapton window
Data collection mode Reflection
Scan method Step
2θ values (°) 2θmin = 5.00 2θmax = 100.01 2θstep = 0.020
 
Refinement
R factors and goodness of fit Rp = 0.020, Rwp = 0.025, Rexp = 0.023, R(F2) = 0.048, χ2 = 1.232
No. of parameters 57
No. of restraints 13
The same symmetry and lattice parameters were used for the DFT calculation. Computer programs: DIFFRAC.Measurement (Bruker, 2009[Bruker (2009). DIFFRAC.Measurement. Bruker AXS Inc., Madison, Wisconsin, USA.]), GSAS (Larson & Von Dreele, 2004[Larson, A. C. & Von Dreele, R. B. (2004). General Structure Analysis System, (GSAS). Report LAUR, 86-784 Los Alamos National Laboratory, New Mexico, USA.]), DIAMOND (Crystal Impact, 2015[Crystal Impact (2015). DIAMOND. Crystal Impact GbR, Bonn, Germany. https://www.crystalimpact.com/diamond.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).
[Figure 4]
Figure 4
Rietveld plot for the refinement of trirubidium citrate. The vertical scale is not the raw counts but the counts multiplied by the least-squares weights. This plot emphasizes the fit of the weaker peaks. The red crosses represent the observed data points, and the green line is the calculated pattern. The magenta curve is the difference pattern, plotted at the same scale as the other patterns. The row of black tick marks indicates the reflection positions. The red tick marks indicate the positions of the peaks of the Si inter­nal standard.

The pattern was indexed using DICVOL06 (Louër & Boultif, 2007[Louër, D. & Boultif, A. (2007). Z. Kristallogr. Suppl. 2007, 191-196.]) on a primitive ortho­rhom­bic cell having a = 7.904, b = 12.701, c = 10.773 Å, and V = 1081.8 Å3. These lattice parameters are 2.6, 1.8, and 3.3% larger than those of K3C6H5O7 (Rammohan & Kaduk, 2016e[Rammohan, A. & Kaduk, J. A. (2016e). Acta Cryst. E72, 1159-1162.]), and the volume is 7.9% larger. The compound was assumed to be isostructural to the K analogue (space group Pna21), and the coordinates of tripotassium citrate were used as the initial model for the Rietveld refinement.

Pseudo-Voigt profile coefficients were as parameterized in Thompson et al. (1987[Thompson, P., Cox, D. E. & Hastings, J. B. (1987). J. Appl. Cryst. 20, 79-83.]) with profile coefficients for Simpson's rule integration of the pseudo-Voigt function according to Howard (1982[Howard, C. J. (1982). J. Appl. Cryst. 15, 615-620.]). The asymmetry correction of Finger et al. (1994[Finger, L. W., Cox, D. E. & Jephcoat, A. P. (1994). J. Appl. Cryst. 27, 892-900.]) was applied, and microstrain broadening by Stephens (1999[Stephens, P. W. (1999). J. Appl. Cryst. 32, 281-289.]). The structure was refined by the Rietveld method using GSAS/EXPGUI (Larson & Von Dreele, 2004[Larson, A. C. & Von Dreele, R. B. (2004). General Structure Analysis System, (GSAS). Report LAUR, 86-784 Los Alamos National Laboratory, New Mexico, USA.]; Toby, 2001[Toby, B. H. (2001). J. Appl. Cryst. 34, 210-213.]). All C—C and C—O bond lengths were restrained, as were all bond angles. The hydrogen atoms were included at fixed positions, which were recalculated during the course of the refinement using Materials Studio (Dassault Systèmes, 2014[Dassault Systèmes (2014). Materials Studio. BIOVIA, San Diego California, USA.]). The Uiso value of the C atom in the central part of the citrate anion, and the C and O atoms on the exterior, were constrained to be equal, and the Uiso valuess of the hydrogen atoms were constrained to be 1.3 times those of the atoms to which they are attached.

The structure refined satisfactorily (Rwp = 0.0301 and reduced χ2 = 1.828 for 69 variables) in space group Pna21 (the space group of the K analogue), but both the ADDSYM module of PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and the Find Symmetry module of Materials Studio (Dassault Systèmes, 2014[Dassault Systèmes (2014). Materials Studio. BIOVIA, San Diego California, USA.]) suggested the presence of an additional centre of symmetry, and that the space group was Pnma (with a transformation of axes). The tolerance on the search was 0.12 Å. Because lower residuals were obtained with fewer parameters, we believe that Pnma is the correct space group.

7. DFT calculations

After the Rietveld refinement, a density functional geometry optimization (fixed experimental unit cell) was carried out using CRYSTAL14 (Dovesi et al., 2014[Dovesi, R., Orlando, R., Erba, A., Zicovich-Wilson, C. M., Civalleri, B., Casassa, S., Maschio, L., Ferrabone, M., De La Pierre, M., D'Arco, P., Noël, Y., Causà, M., Rérat, M. & Kirtman, B. (2014). Int. J. Quantum Chem. 114, 1287-1317.]). The basis sets for the C, H, and O atoms were those of Peintinger et al. (2012[Peintinger, M. F., Oliveira, D. V. & Bredow, T. (2012). J. Comput. Chem. 34, 451-459.]), and the basis set for Rb was that of Schoenes et al. (2008[Schoenes, J., Racu, A.-M., Doll, K., Bukowski, Z. & Karpinski, J. (2008). Phys. Rev. B, 77, 134515.]). The calculation was run on eight 2.1 GHz Xeon cores (each with 6 Gb RAM) of a 304-core Dell Linux cluster at IIT, used 8 k-points and the B3LYP functional, and took about seven h. The Uiso values from the Rietveld refinement were assigned to the optimized fractional coordinates.

Supporting information


Computing details top

Data collection: DIFFRAC.Measurement (Bruker, 2009) for RAMM077C_phase_1. Molecular graphics: DIAMOND (Crystal Impact, 2015) for RAMM077C_phase_1. Software used to prepare material for publication: publCIF (Westrip, 2010) for RAMM077C_phase_1.

(RAMM077C_phase_1) Trirubidium citrate top
Crystal data top
3Rb+·C6H5O73c = 12.6986 (3) Å
Mr = 445.50V = 1082.08 (7) Å3
Orthorhombic, PnmaZ = 4
Hall symbol: -P 2ac 2nDx = 2.735 Mg m3
a = 7.9096 (2) ÅT = 300 K
b = 10.7733 (3) Å
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.8481 (8)0.5192 (4)0.1236 (8)0.0129 (18)*
C20.9284 (10)0.6373 (4)0.0836 (8)0.028 (5)*
C30.8129 (13)0.750.1037 (8)0.028 (5)*
C60.6630 (17)0.750.0251 (11)0.0129 (18)*
H71.035490.65170.123020.036 (6)*
H80.94520.629630.002570.036 (6)*
O110.6988 (9)0.4914 (7)0.0961 (6)0.0129 (18)*
O120.9397 (9)0.4386 (5)0.1695 (6)0.0129 (18)*
O150.6865 (17)0.750.0763 (10)0.0129 (18)*
O160.5218 (18)0.750.0658 (10)0.0129 (18)*
O170.7506 (12)0.750.2090 (9)0.0129 (18)*
H180.619550.750.193130.017 (2)*
Rb190.3442 (2)0.97103 (16)0.12323 (13)0.0255 (6)*
Rb200.1377 (4)0.250.29027 (16)0.0255 (6)*
Geometric parameters (Å, º) top
C1—C21.5102 (11)O15—Rb20viii3.074 (13)
C1—O111.267 (3)O15—Rb20ix3.053 (14)
C1—O121.272 (3)O16—C61.231 (19)
C2—C11.5102 (11)O16—Rb192.859 (8)
C2—C31.5410 (11)O16—Rb19i2.859 (8)
C2—H70.996 (9)O16—Rb20viii3.719 (13)
C2—H81.105 (10)O17—C31.425 (3)
C3—C21.5410 (11)O17—H181.056 (9)
C3—C2i1.5410 (11)O17—Rb19ii3.280 (8)
C3—C61.5502 (11)O17—Rb19x3.280 (8)
C3—O171.425 (3)H18—O171.056 (9)
C6—C31.5502 (11)Rb19—O11i2.855 (7)
C6—O151.300 (16)Rb19—O11xi3.766 (7)
C6—O161.231 (19)Rb19—O11xii2.815 (8)
H7—C20.996 (9)Rb19—O12xiii3.395 (7)
H8—C21.105 (10)Rb19—O12xi2.906 (7)
O11—C11.267 (3)Rb19—O15vii3.074 (3)
O11—Rb19i2.855 (7)Rb19—O162.859 (8)
O11—Rb19ii3.766 (7)Rb19—O17xi3.280 (8)
O11—Rb19iii2.815 (8)Rb20—O11xiv3.013 (7)
O11—Rb20iv3.013 (7)Rb20—O11xv3.013 (7)
O12—C11.272 (3)Rb20—O12xvi2.989 (6)
O12—Rb19v3.395 (7)Rb20—O12xvii2.989 (6)
O12—Rb19ii2.906 (7)Rb20—O12xiv3.178 (7)
O12—Rb20vi2.989 (6)Rb20—O12xv3.178 (7)
O12—Rb20iv3.178 (7)Rb20—O15xviii3.074 (13)
O15—C61.300 (16)Rb20—O15ix3.053 (14)
O15—Rb19vii3.074 (3)Rb20—O16xviii3.719 (13)
O15—Rb19iii3.074 (3)
C2—C1—O11119.9 (3)Rb19xix—O17—Rb19xxi93.1 (3)
C2—C1—O12119.3 (3)O11i—Rb19—O11xxii89.3 (2)
C2—C1—Rb19xix108.2 (5)O11i—Rb19—O12xiii155.0 (2)
O11—C1—O12119.7 (3)O11i—Rb19—O12xxiii78.8 (2)
C1—C2—C3111.0 (3)O11i—Rb19—O15vii85.2 (3)
C1—C2—H7108.7 (5)O11i—Rb19—O1666.7 (3)
C1—C2—H8108.7 (7)O11i—Rb19—O17xxiii113.8 (3)
C3—C2—H7107.3 (6)O11xxii—Rb19—O12xiii92.01 (17)
C3—C2—H8107.1 (5)O11xxii—Rb19—O12xxiii154.38 (18)
H7—C2—H8114.0 (8)O11xxii—Rb19—O15vii73.9 (3)
C2—C3—C2i104.0 (6)O11xxii—Rb19—O1682.6 (3)
C2—C3—C6110.3 (3)O11xxii—Rb19—O17xxiii132.2 (2)
C2—C3—O17111.2 (3)O12xiii—Rb19—O12xxiii89.55 (15)
C2i—C3—C6110.3 (3)O12xiii—Rb19—O15vii71.3 (3)
C2i—C3—O17111.2 (3)O12xiii—Rb19—O16138.2 (3)
C6—C3—O17109.9 (3)O12xiii—Rb19—O17xxiii83.3 (2)
C3—C6—O15121.9 (10)O12xxiii—Rb19—O15vii82.5 (3)
C3—C6—O16115.1 (10)O12xxiii—Rb19—O16112.5 (3)
O15—C6—O16123.0 (11)O12xxiii—Rb19—O17xxiii73.4 (2)
C1—O11—Rb19i148.1 (7)O15vii—Rb19—O16143.5 (3)
C1—O11—Rb19xii113.8 (6)O15vii—Rb19—O17xxiii144.9 (3)
C1—O11—Rb20xx102.8 (3)O16—Rb19—O17xxiii70.9 (3)
Rb19i—O11—Rb19xii90.7 (2)O11xxiv—Rb20—O11xxv119.3 (3)
Rb19i—O11—Rb20xx84.7 (2)O11xxiv—Rb20—O12xvi156.4 (3)
Rb19xii—O11—Rb20xx112.8 (3)O11xxiv—Rb20—O12xvii75.1 (2)
C1—O12—Rb19v105.2 (4)O11xxiv—Rb20—O12xxiv41.44 (11)
C1—O12—Rb19xix92.2 (6)O11xxiv—Rb20—O12xxv110.8 (2)
C1—O12—Rb20vi175.9 (6)O11xxiv—Rb20—O15xviii82.52 (19)
C1—O12—Rb20xx94.7 (3)O11xxiv—Rb20—O15ix110.68 (17)
Rb19v—O12—Rb19xix107.8 (2)O11xxv—Rb20—O12xvi75.1 (2)
Rb19v—O12—Rb20vi77.87 (16)O11xxv—Rb20—O12xvii156.4 (3)
Rb19v—O12—Rb20xx156.85 (19)O11xxv—Rb20—O12xxiv110.8 (2)
Rb19xix—O12—Rb20vi84.22 (19)O11xxv—Rb20—O12xxv41.44 (11)
Rb19xix—O12—Rb20xx82.72 (18)O11xxv—Rb20—O15xviii82.52 (19)
Rb20vi—O12—Rb20xx82.91 (15)O11xxv—Rb20—O15ix110.68 (17)
C6—O15—Rb19vii100.4 (3)O12xvi—Rb20—O12xvii85.7 (3)
C6—O15—Rb19xii100.4 (3)O12xvi—Rb20—O12xxiv155.67 (15)
C6—O15—Rb20viii115.2 (9)O12xvi—Rb20—O12xxv92.37 (19)
C6—O15—Rb20ix161.1 (10)O12xvi—Rb20—O15xviii81.1 (2)
Rb19vii—O15—Rb19xii155.8 (5)O12xvi—Rb20—O15ix77.4 (2)
Rb19vii—O15—Rb20viii80.0 (2)O12xvii—Rb20—O12xxiv92.37 (19)
Rb19vii—O15—Rb20ix82.1 (3)O12xvii—Rb20—O12xxv155.67 (15)
Rb19xii—O15—Rb20viii80.0 (2)O12xvii—Rb20—O15xviii81.1 (2)
Rb19xii—O15—Rb20ix82.1 (3)O12xvii—Rb20—O15ix77.4 (2)
Rb20viii—O15—Rb20ix83.6 (3)O12xxiv—Rb20—O12xxv79.5 (2)
C6—O16—Rb19123.6 (2)O12xxiv—Rb20—O15xviii122.6 (2)
C6—O16—Rb19i123.6 (2)O12xxiv—Rb20—O15ix78.5 (2)
Rb19—O16—Rb19i112.8 (5)O12xxv—Rb20—O15xviii122.6 (2)
C3—O17—H1899.2 (8)O12xxv—Rb20—O15ix78.5 (2)
C3—O17—Rb19xix122.1 (3)O15xviii—Rb20—O15ix150.6 (4)
C3—O17—Rb19xxi122.1 (3)
Symmetry codes: (i) x, y+3/2, z; (ii) x+1/2, y+3/2, z+1/2; (iii) x+1, y1/2, z; (iv) x+1/2, y+1/2, z+1/2; (v) x+1, y+3/2, z; (vi) x+1, y, z; (vii) x+1, y+2, z; (viii) x+1/2, y+1/2, z1/2; (ix) x+1, y+1, z; (x) x+1/2, y, z+1/2; (xi) x1/2, y+3/2, z+1/2; (xii) x+1, y+1/2, z; (xiii) x1, y+3/2, z; (xiv) x1/2, y+1/2, z+1/2; (xv) x1/2, y, z+1/2; (xvi) x1, y, z; (xvii) x1, y+1/2, z; (xviii) x+1/2, y1/2, z+1/2; (xix) x+3/2, y+5/2, z+3/2; (xx) x+3/2, y+3/2, z+3/2; (xxi) x+3/2, y, z+3/2; (xxii) x+1, y+3/2, z; (xxiii) x+1/2, y+5/2, z+3/2; (xxiv) x+1/2, y+3/2, z+3/2; (xxv) x+1/2, y, z+3/2.
(RAMM077C_phase_2) top
Crystal data top
SiV = 160.20 Å3
Mr = 28.09Z = 8
Cubic, Fd3mDx = 2.329 Mg m3
Hall symbol: -F 4vw 2vwT = 300 K
a = 5.43105 Å
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Si10.1250.1250.1250.01*
Geometric parameters (Å, º) top
Si1—Si1i2.3517Si1—Si1iii2.3517
Si1—Si1ii2.3517Si1—Si1iv2.3517
Si1i—Si1—Si1ii109.4712Si1ii—Si1—Si1iii109.4712
Si1i—Si1—Si1iii109.4712Si1ii—Si1—Si1iv109.4712
Si1i—Si1—Si1iv109.4712Si1iii—Si1—Si1iv109.4712
Symmetry codes: (i) x+1/4, y+1/4, z; (ii) z, x+1/4, y+1/4; (iii) y+1/4, z, x+1/4; (iv) x, y, z.
(ramm077c_DFT) top
Crystal data top
C6H5O7Rb3b = 10.7733 Å
Mr = 445.50c = 12.6986 Å
Orthorhombic, PnmaV = 1082.08 Å3
a = 7.9096 ÅZ = 4
Data collection top
h = l =
k =
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.856520.512370.117620.01290*
C20.927100.636660.081560.02780*
H71.044040.653300.124250.03610*
H80.958790.631560.001990.03610*
O110.705730.486060.094690.01290*
O120.956200.441750.168220.01290*
Rb190.343290.971830.128070.02550*
C30.814080.750000.098680.02780*
C60.658460.750000.023690.01290*
O150.685020.750000.074310.01290*
O160.515590.750000.067820.01290*
O170.752590.750000.206450.01290*
H180.629750.750000.196090.01680*
Rb200.149600.250000.293680.02550*
Bond lengths (Å) top
C1—C21.521C3—C2i1.529
C1—O111.260C3—C61.556
C1—O121.270C3—O171.452
C2—C31.529C6—O151.262
C2—H71.087C6—O161.261
C2—H81.092O17—H180.981
Symmetry code: (i) x, y+3/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O17—H18···O160.9811.8622.572126.7
 

Acknowledgements

We thank Andrey Rogachev for the use of computing resources at IIT.

References

First citationBravais, A. (1866). In Études Cristallographiques. Paris: Gauthier Villars.  Google Scholar
First citationBruker (2009). DIFFRAC.Measurement. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCrystal Impact (2015). DIAMOND. Crystal Impact GbR, Bonn, Germany. https://www.crystalimpact.com/diamondGoogle Scholar
First citationDassault Systèmes (2014). Materials Studio. BIOVIA, San Diego California, USA.  Google Scholar
First citationDonnay, J. D. H. & Harker, D. (1937). Am. Mineral. 22, 446–467.  CAS Google Scholar
First citationDovesi, R., Orlando, R., Erba, A., Zicovich-Wilson, C. M., Civalleri, B., Casassa, S., Maschio, L., Ferrabone, M., De La Pierre, M., D'Arco, P., Noël, Y., Causà, M., Rérat, M. & Kirtman, B. (2014). Int. J. Quantum Chem. 114, 1287–1317.  Web of Science CrossRef CAS Google Scholar
First citationFinger, L. W., Cox, D. E. & Jephcoat, A. P. (1994). J. Appl. Cryst. 27, 892–900.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationFriedel, G. (1907). Bull. Soc. Fr. Mineral. 30, 326–455.  Google Scholar
First citationGroom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationHoward, C. J. (1982). J. Appl. Cryst. 15, 615–620.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationKaduk, J. A. & Stern, C. (2016a). CSD Communication 1446457–1446458. CCDC, Cambridge, England.  Google Scholar
First citationKaduk, J. A. & Stern, C. (2016b). CSD Communication 1446460–1446461. CCDC, Cambridge, England.  Google Scholar
First citationLarson, A. C. & Von Dreele, R. B. (2004). General Structure Analysis System, (GSAS). Report LAUR, 86–784 Los Alamos National Laboratory, New Mexico, USA.  Google Scholar
First citationLouër, D. & Boultif, A. (2007). Z. Kristallogr. Suppl. 2007, 191–196.  Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationPeintinger, M. F., Oliveira, D. V. & Bredow, T. (2012). J. Comput. Chem. 34, 451–459.  CrossRef Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2016a). Acta Cryst. E72, 170–173.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2016b). Acta Cryst. E72, 403–406.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2016c). Acta Cryst. E72, 793–796.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2016d). Acta Cryst. E72, 854–857.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2016e). Acta Cryst. E72, 1159–1162.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2017a). Acta Cryst. B73. Submitted.  Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2017b). Acta Cryst. E73, 92–95.  CSD CrossRef IUCr Journals Google Scholar
First citationRammohan, A. & Kaduk, J. A. (2017c). Acta Cryst. E73, 286–290.  CrossRef IUCr Journals Google Scholar
First citationRammohan, A., Sarjeant, A. A. & Kaduk, J. A. (2016). Acta Cryst. E72, 943–946.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSchoenes, J., Racu, A.-M., Doll, K., Bukowski, Z. & Karpinski, J. (2008). Phys. Rev. B, 77, 134515.  Web of Science CrossRef Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStephens, P. W. (1999). J. Appl. Cryst. 32, 281–289.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStreek, J. van de & Neumann, M. A. (2014). Acta Cryst. B70, 1020–1032.  Web of Science CrossRef IUCr Journals Google Scholar
First citationThompson, P., Cox, D. E. & Hastings, J. B. (1987). J. Appl. Cryst. 20, 79–83.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationToby, B. H. (2001). J. Appl. Cryst. 34, 210–213.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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