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Hexaaquamagnesium(II) sulfate pentahydrate, [Mg(H
2O)
6]SO
4·5H
2O, and hexaaquamagnesium(II) chromate(II) pentahydrate, [Mg(H
2O)
6][CrO
4]·5H
2O, are isomorphous, being composed of hexaaquamagnesium(II) octahedra, [Mg(H
2O)
6]
2+, and sulfate (chromate) tetrahedral oxyanions, SO
42− (CrO
42−), linked by hydrogen bonds. There are two symmetry-inequivalent centrosymmetric octahedra:
M1 at (0, 0, 0) donates hydrogen bonds directly to the tetrahedral oxyanion,
T1, at (0.405, 0.320, 0.201), whereas the
M2 octahedron at (0, 0,
![{1 \over 2}](//journals.iucr.org/c/issues/2013/04/00/ku3086//teximages/ku3086fi1.gif)
) is linked to the oxyanion
via five interstitial water molecules. Substitution of Cr
VI for S
VI leads to a substantial expansion of
T1, since the Cr—O bond is approximately 12% longer than the S—O bond. This expansion is propagated through the hydrogen-bonded framework to produce a 3.3% increase in unit-cell volume; the greatest part of this chemically induced strain is manifested along the
b* direction. The hydrogen bonds in the chromate compound mitigate ∼20% of the expected strain due to the larger oxyanion, becoming shorter (
i.e. stronger) and more linear than in the sulfate analogue. The bifurcated hydrogen bond donated by one of the interstitial water molecules is significantly more symmetrical in the chromate analogue.
Supporting information
For both compounds, data collection: SXD2001 (Gutmann, 2005); cell refinement: SXD2001 (Gutmann, 2005); data reduction: SXD2001 (Gutmann, 2005); program(s) used to solve structure: n/a; program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).
(I) Hexaaquamagnesium(II) sulfate pentahydrate
top
Crystal data top
[Mg(H2O)6](SO4)·5H2O | Z = 2 |
Mr = 318.53 | F(000) = 26 |
Triclinic, P1 | Dx = 1.508 Mg m−3 |
a = 6.7283 (13) Å | Melting point: 275 K |
b = 6.7839 (14) Å | Neutron radiation, λ = 0.48-7.0 Å |
c = 17.332 (4) Å | Cell parameters from 550 reflections |
α = 88.181 (13)° | µ = 0.0 mm−1 |
β = 89.349 (14)° | T = 5 K |
γ = 62.515 (12)° | Cuboid, colourless |
V = 701.5 (2) Å3 | 2.00 × 2.00 × 2.00 mm |
Data collection top
SXD beamline diffractometer | Rint = 0.000 |
Radiation source: ISIS neutron spallation source | θmax = 84.9°, θmin = 9.0° |
time–of–flight Laue diffraction scans | h = −17→16 |
14936 measured reflections | k = −18→16 |
14936 independent reflections | l = −37→25 |
14936 reflections with I > 2σ(I) | |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.067 | All H-atom parameters refined |
wR(F2) = 0.187 | w = 1/[σ2(Fo2) + (0.1001P)2 + 16.5668P] where P = (Fo2 + 2Fc2)/3 |
S = 1.11 | (Δ/σ)max = 0.001 |
14936 reflections | Δρmax = 1.97 e Å−3 |
367 parameters | Δρmin = −2.09 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0187 (4) |
Special details top
Experimental. For peak integration a local UB matrix refined for each frame, using
approximately 50 reflections from each of the 11 detectors. Hence
_cell_measurement_reflns_used 550
For final cell dimensions a weighted average of all local cells was calculated.
Because of the nature of the experiment, it is not possible to give values of
theta_min and theta_max for the cell determination. The same applies for the
wavelength used for the experiment. The range of wavelengths used was
0.48–7.0 Angstroms, BUT the bulk of the diffraction information is obtained
from wavelengths in the range 0.7–2.5 Angstroms. The data-collection
procedures on the SXD instrument used for the single-crystal neutron data
collection are most recently summarized in the Appendix to the following paper:
Wilson, C.C. (1997). J. Mol. Struct. 405, 207–217 |
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. The variable wavelength nature of the data collection procedure means that
sensible values of _diffrn_reflns_theta_min & _diffrn_reflns_theta_max cannot
be given. Instead, the following limits are given:
_diffrn_reflns_sin(theta)/lambda_min 0.06
_diffrn_reflns_sin(theta)/lambda_max 1.38
_refine_diff_density_max/min is given in Fermi per per angstrom cubed not
electrons per angstrom cubed. Another way to consider the _refine_diff_density_
is as a percentage of the scattering density of a given atom:
_refine_diff_density_max = 4% of oxygen
_refine_diff_density_min = -4% of oxygen
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Mg1 | 1.0000 | 0.0000 | 0.0000 | 0.00309 (17) | |
OW1 | 0.65691 (14) | 0.17344 (16) | 0.00821 (6) | 0.00641 (14) | |
H1A | 0.5556 (4) | 0.2338 (5) | 0.05090 (16) | 0.0226 (5) | |
H1B | 0.5648 (4) | 0.1897 (4) | −0.03695 (15) | 0.0195 (4) | |
OW2 | 0.99062 (15) | −0.26902 (14) | 0.05542 (7) | 0.00605 (14) | |
H2A | 1.1165 (4) | −0.4050 (4) | 0.07339 (18) | 0.0214 (4) | |
H2B | 0.8563 (3) | −0.2707 (4) | 0.07618 (16) | 0.0187 (4) | |
OW3 | 1.04714 (15) | 0.11065 (15) | 0.10544 (6) | 0.00586 (14) | |
H3A | 1.0430 (5) | 0.0428 (4) | 0.15481 (15) | 0.0210 (4) | |
H3B | 1.1320 (4) | 0.1928 (4) | 0.11117 (16) | 0.0209 (4) | |
Mg2 | 1.0000 | 0.0000 | 0.5000 | 0.00292 (17) | |
OW4 | 1.15158 (14) | −0.11150 (15) | 0.39413 (6) | 0.00532 (13) | |
H4A | 1.3000 (3) | −0.1225 (4) | 0.38388 (15) | 0.0181 (4) | |
H4B | 1.0784 (4) | −0.0869 (4) | 0.34364 (15) | 0.0182 (4) | |
OW5 | 0.80442 (16) | −0.15462 (16) | 0.48629 (7) | 0.00664 (14) | |
H5A | 0.7715 (4) | −0.2430 (4) | 0.52506 (16) | 0.0200 (4) | |
H5B | 0.7129 (4) | −0.1394 (4) | 0.44090 (16) | 0.0195 (4) | |
OW6 | 0.75619 (14) | 0.28506 (15) | 0.44646 (6) | 0.00600 (14) | |
H6A | 0.7997 (4) | 0.3342 (4) | 0.39855 (16) | 0.0192 (4) | |
H6B | 0.6015 (3) | 0.3155 (4) | 0.43816 (17) | 0.0197 (4) | |
S1 | 0.4053 (2) | 0.3200 (3) | 0.20064 (11) | 0.0020 (2) | |
O1 | 0.31690 (14) | 0.33018 (14) | 0.12243 (6) | 0.00443 (13) | |
O2 | 0.21813 (14) | 0.43819 (14) | 0.25486 (6) | 0.00484 (13) | |
O3 | 0.53006 (14) | 0.08315 (14) | 0.22698 (6) | 0.00493 (13) | |
O4 | 0.55692 (14) | 0.42090 (15) | 0.20021 (6) | 0.00561 (14) | |
OW7 | 0.31115 (15) | 0.40412 (15) | 0.41252 (6) | 0.00597 (14) | |
H7A | 0.2872 (4) | 0.4092 (4) | 0.35678 (15) | 0.0202 (4) | |
H7B | 0.2379 (4) | 0.5584 (4) | 0.42643 (19) | 0.0246 (5) | |
OW8 | 0.60549 (15) | −0.24763 (15) | 0.11976 (6) | 0.00598 (14) | |
H8A | 0.5589 (4) | −0.1284 (4) | 0.15631 (16) | 0.0201 (4) | |
H8B | 0.5906 (4) | −0.3698 (4) | 0.14565 (17) | 0.0205 (4) | |
OW9 | 0.56102 (15) | −0.14706 (15) | 0.36038 (6) | 0.00562 (13) | |
H9A | 0.5357 (4) | −0.0430 (4) | 0.31630 (16) | 0.0192 (4) | |
H9B | 0.6588 (4) | −0.2941 (3) | 0.33980 (16) | 0.0185 (4) | |
OW10 | 0.83217 (15) | 0.43812 (16) | 0.30797 (6) | 0.00604 (14) | |
H10A | 0.7453 (4) | 0.4115 (4) | 0.26813 (16) | 0.0195 (4) | |
H10B | 0.9726 (4) | 0.4156 (4) | 0.28472 (16) | 0.0204 (4) | |
OW11 | 0.99540 (15) | −0.09053 (15) | 0.24597 (7) | 0.00620 (14) | |
H11A | 1.0629 (4) | −0.2510 (3) | 0.24017 (17) | 0.0206 (4) | |
H11B | 0.8344 (3) | −0.0324 (4) | 0.23867 (16) | 0.0194 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Mg1 | 0.0020 (3) | 0.0035 (3) | 0.0033 (5) | −0.0009 (3) | 0.0001 (3) | −0.0002 (3) |
OW1 | 0.0027 (2) | 0.0092 (3) | 0.0057 (4) | −0.0014 (2) | 0.0003 (2) | −0.0013 (3) |
H1A | 0.0161 (8) | 0.0311 (11) | 0.0151 (11) | −0.0058 (7) | 0.0073 (7) | −0.0080 (9) |
H1B | 0.0150 (7) | 0.0279 (10) | 0.0139 (10) | −0.0082 (7) | −0.0035 (6) | −0.0019 (8) |
OW2 | 0.0045 (2) | 0.0048 (3) | 0.0082 (4) | −0.0018 (2) | 0.0005 (2) | 0.0018 (3) |
H2A | 0.0144 (7) | 0.0152 (7) | 0.0271 (13) | −0.0008 (6) | −0.0029 (7) | 0.0061 (8) |
H2B | 0.0129 (7) | 0.0216 (8) | 0.0232 (11) | −0.0095 (6) | 0.0032 (7) | 0.0017 (8) |
OW3 | 0.0066 (3) | 0.0083 (3) | 0.0041 (4) | −0.0047 (2) | 0.0004 (2) | −0.0009 (3) |
H3A | 0.0291 (10) | 0.0277 (10) | 0.0111 (10) | −0.0177 (9) | −0.0008 (8) | 0.0050 (8) |
H3B | 0.0261 (10) | 0.0261 (9) | 0.0195 (12) | −0.0198 (8) | −0.0014 (8) | −0.0010 (9) |
Mg2 | 0.0026 (3) | 0.0031 (3) | 0.0031 (5) | −0.0014 (3) | 0.0000 (3) | −0.0003 (3) |
OW4 | 0.0041 (2) | 0.0078 (3) | 0.0037 (4) | −0.0023 (2) | 0.0006 (2) | −0.0010 (3) |
H4A | 0.0119 (6) | 0.0245 (9) | 0.0190 (11) | −0.0094 (6) | 0.0026 (6) | −0.0019 (8) |
H4B | 0.0175 (7) | 0.0245 (9) | 0.0118 (10) | −0.0090 (7) | −0.0040 (6) | 0.0003 (8) |
OW5 | 0.0078 (3) | 0.0094 (3) | 0.0055 (4) | −0.0064 (2) | −0.0016 (3) | 0.0015 (3) |
H5A | 0.0257 (9) | 0.0248 (9) | 0.0159 (11) | −0.0174 (8) | 0.0001 (8) | 0.0056 (8) |
H5B | 0.0201 (8) | 0.0251 (9) | 0.0159 (11) | −0.0127 (7) | −0.0071 (7) | 0.0012 (8) |
OW6 | 0.0038 (2) | 0.0062 (3) | 0.0063 (4) | −0.0010 (2) | −0.0003 (2) | 0.0016 (3) |
H6A | 0.0178 (8) | 0.0230 (9) | 0.0160 (11) | −0.0094 (7) | 0.0015 (7) | 0.0062 (7) |
H6B | 0.0101 (6) | 0.0251 (9) | 0.0232 (12) | −0.0077 (6) | −0.0013 (6) | 0.0018 (8) |
S1 | 0.0013 (4) | 0.0026 (4) | 0.0020 (7) | −0.0009 (3) | 0.0003 (4) | −0.0004 (4) |
O1 | 0.0042 (2) | 0.0060 (3) | 0.0030 (4) | −0.0022 (2) | −0.0009 (2) | −0.0006 (2) |
O2 | 0.0032 (2) | 0.0056 (3) | 0.0045 (4) | −0.0008 (2) | 0.0019 (2) | −0.0017 (3) |
O3 | 0.0047 (2) | 0.0032 (2) | 0.0056 (4) | −0.0007 (2) | −0.0003 (2) | 0.0007 (2) |
O4 | 0.0052 (3) | 0.0076 (3) | 0.0065 (4) | −0.0052 (2) | −0.0005 (2) | 0.0004 (3) |
OW7 | 0.0059 (3) | 0.0057 (3) | 0.0061 (4) | −0.0025 (2) | 0.0002 (2) | −0.0001 (3) |
H7A | 0.0231 (9) | 0.0258 (9) | 0.0101 (10) | −0.0100 (8) | −0.0006 (7) | 0.0000 (8) |
H7B | 0.0251 (10) | 0.0139 (7) | 0.0304 (15) | −0.0050 (7) | 0.0027 (9) | −0.0081 (9) |
OW8 | 0.0059 (3) | 0.0068 (3) | 0.0058 (4) | −0.0034 (2) | 0.0001 (2) | −0.0002 (3) |
H8A | 0.0235 (9) | 0.0174 (7) | 0.0194 (11) | −0.0090 (7) | 0.0047 (8) | −0.0077 (8) |
H8B | 0.0266 (10) | 0.0175 (8) | 0.0215 (12) | −0.0139 (7) | 0.0011 (8) | 0.0034 (8) |
OW9 | 0.0052 (3) | 0.0072 (3) | 0.0044 (4) | −0.0028 (2) | 0.0003 (2) | −0.0002 (3) |
H9A | 0.0214 (8) | 0.0179 (8) | 0.0168 (11) | −0.0080 (7) | −0.0004 (7) | 0.0056 (7) |
H9B | 0.0181 (7) | 0.0137 (7) | 0.0200 (11) | −0.0040 (6) | 0.0023 (7) | −0.0036 (7) |
OW10 | 0.0055 (3) | 0.0082 (3) | 0.0052 (4) | −0.0038 (2) | 0.0003 (2) | −0.0004 (3) |
H10A | 0.0199 (8) | 0.0260 (9) | 0.0164 (11) | −0.0136 (7) | −0.0035 (7) | −0.0022 (8) |
H10B | 0.0128 (7) | 0.0266 (9) | 0.0223 (12) | −0.0095 (7) | 0.0057 (7) | −0.0034 (9) |
OW11 | 0.0053 (3) | 0.0065 (3) | 0.0061 (4) | −0.0021 (2) | −0.0003 (2) | −0.0001 (3) |
H11A | 0.0206 (8) | 0.0120 (6) | 0.0256 (13) | −0.0043 (6) | 0.0013 (8) | −0.0044 (8) |
H11B | 0.0106 (6) | 0.0215 (8) | 0.0228 (12) | −0.0047 (6) | −0.0010 (6) | 0.0002 (8) |
Geometric parameters (Å, º) top
Mg1—OW1 | 2.0566 (9) | OW4—H4B | 0.980 (3) |
Mg1—OW1i | 2.0566 (9) | OW5—H5A | 0.977 (3) |
Mg1—OW2 | 2.0617 (11) | OW5—H5B | 0.978 (3) |
Mg1—OW2i | 2.0618 (10) | OW6—H6A | 0.976 (3) |
Mg1—OW3 | 2.0794 (10) | OW6—H6B | 0.975 (2) |
Mg1—OW3i | 2.0794 (10) | S1—O4 | 1.4673 (17) |
OW1—H1A | 0.964 (2) | S1—O1 | 1.473 (2) |
OW1—H1B | 0.975 (3) | S1—O2 | 1.4836 (17) |
OW2—H2A | 0.965 (2) | S1—O3 | 1.4875 (19) |
OW2—H2B | 0.974 (2) | OW7—H7A | 0.978 (3) |
OW3—H3A | 0.965 (3) | OW7—H7B | 0.966 (2) |
OW3—H3B | 0.972 (2) | OW8—H8A | 0.973 (2) |
Mg2—OW5 | 2.0458 (9) | OW8—H8B | 0.975 (3) |
Mg2—OW5ii | 2.0458 (9) | OW9—H9A | 0.984 (3) |
Mg2—OW6 | 2.0699 (11) | OW9—H9B | 0.983 (2) |
Mg2—OW6ii | 2.0699 (11) | OW10—H10A | 0.983 (2) |
Mg2—OW4ii | 2.0767 (10) | OW10—H10B | 0.970 (2) |
Mg2—OW4 | 2.0767 (10) | OW11—H11A | 0.975 (2) |
OW4—H4A | 0.981 (2) | OW11—H11B | 0.975 (2) |
| | | |
OW1—Mg1—OW1i | 180.0 | OW5—Mg2—OW4ii | 89.25 (4) |
OW1—Mg1—OW2 | 89.36 (4) | OW5ii—Mg2—OW4ii | 90.75 (4) |
OW1i—Mg1—OW2 | 90.64 (4) | OW6—Mg2—OW4ii | 89.77 (4) |
OW1—Mg1—OW2i | 90.64 (4) | OW6ii—Mg2—OW4ii | 90.23 (4) |
OW1i—Mg1—OW2i | 89.36 (4) | OW5—Mg2—OW4 | 90.75 (4) |
OW2—Mg1—OW2i | 180.0 | OW5ii—Mg2—OW4 | 89.25 (4) |
OW1—Mg1—OW3 | 92.58 (4) | OW6—Mg2—OW4 | 90.23 (4) |
OW1i—Mg1—OW3 | 87.42 (4) | OW6ii—Mg2—OW4 | 89.77 (4) |
OW2—Mg1—OW3 | 90.06 (4) | OW4ii—Mg2—OW4 | 180.0 |
OW2i—Mg1—OW3 | 89.94 (4) | Mg2—OW4—H4A | 119.50 (16) |
OW1—Mg1—OW3i | 87.42 (4) | Mg2—OW4—H4B | 127.50 (15) |
OW1i—Mg1—OW3i | 92.58 (4) | H4A—OW4—H4B | 105.8 (2) |
OW2—Mg1—OW3i | 89.94 (4) | Mg2—OW5—H5A | 127.10 (17) |
OW2i—Mg1—OW3i | 90.06 (4) | Mg2—OW5—H5B | 125.54 (18) |
OW3—Mg1—OW3i | 179.999 (2) | H5A—OW5—H5B | 107.0 (2) |
Mg1—OW1—H1A | 133.41 (19) | Mg2—OW6—H6A | 116.31 (15) |
Mg1—OW1—H1B | 119.44 (15) | Mg2—OW6—H6B | 124.88 (18) |
H1A—OW1—H1B | 106.7 (2) | H6A—OW6—H6B | 105.0 (2) |
Mg1—OW2—H2A | 127.25 (17) | O4—S1—O1 | 110.31 (13) |
Mg1—OW2—H2B | 125.06 (16) | O4—S1—O2 | 109.66 (10) |
H2A—OW2—H2B | 106.9 (2) | O1—S1—O2 | 110.04 (11) |
Mg1—OW3—H3A | 124.24 (15) | O4—S1—O3 | 109.34 (11) |
Mg1—OW3—H3B | 123.21 (19) | O1—S1—O3 | 108.82 (10) |
H3A—OW3—H3B | 108.4 (2) | O2—S1—O3 | 108.64 (13) |
OW5—Mg2—OW5ii | 179.998 (1) | H7A—OW7—H7B | 104.1 (3) |
OW5—Mg2—OW6 | 89.93 (4) | H8A—OW8—H8B | 107.1 (2) |
OW5ii—Mg2—OW6 | 90.07 (4) | H9A—OW9—H9B | 104.3 (2) |
OW5—Mg2—OW6ii | 90.07 (4) | H10A—OW10—H10B | 107.3 (2) |
OW5ii—Mg2—OW6ii | 89.93 (4) | H11A—OW11—H11B | 107.0 (2) |
OW6—Mg2—OW6ii | 180.0 | | |
Symmetry codes: (i) −x+2, −y, −z; (ii) −x+2, −y, −z+1. |
(II) Hexaaquamagnesium(II) chromate pentahydrate
top
Crystal data top
[Mg(H2O)6](CrO4)·H2O | V = 724.8 (4) Å3 |
Mr = 338.46 | Z = 2 |
Triclinic, P1 | F(000) = 28 |
a = 6.7721 (18) Å | Dx = 1.551 Mg m−3 |
b = 6.917 (2) Å | Neutron radiation, λ = 0.48-7.0 Å |
c = 17.410 (5) Å | Cell parameters from 330 reflections |
α = 88.21 (2)° | T = 10 K |
β = 89.43 (2)° | Cuboid, yellow |
γ = 62.768 (18)° | 2.00 × 2.00 × 2.00 mm |
Data collection top
SXD beamline diffractometer | 8624 independent reflections |
Radiation source: ISIS neutron spallation source | 8624 reflections with I > 2σ(I) |
Detector resolution: 0 pixels mm-1 | Rint = 0.000 |
time–of–flight Laue diffraction scans | θmax = 88.4°, θmin = 8.0° |
Absorption correction: numerical The linear absorption coefficient is wavelength-dependent and is calculated as:
µ = 4.595 + 0.015 λ [cm-1], as determined by Gaussian integration in
SXD2001 (Gutmann, 2005) | h = −15→16 |
| k = −15→13 |
8624 measured reflections | l = −46→40 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.083 | All H-atom parameters refined |
wR(F2) = 0.224 | w = 1/[σ2(Fo2) + (0.1187P)2 + 33.4697P] where P = (Fo2 + 2Fc2)/3 |
S = 1.11 | (Δ/σ)max < 0.001 |
8624 reflections | Δρmax = 1.88 e Å−3 |
369 parameters | Δρmin = −1.66 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0079 (3) |
Special details top
Experimental. For peak integration a local UB matrix refined for each frame, using
approximately 30 reflections from each of the 11 detectors. Hence
_cell_measurement_reflns_used 330
For final cell dimensions a weighted average of all local cells was calculated.
Because of the nature of the experiment, it is not possible to give values of
theta_min and theta_max for the cell determination. The same applies for the
wavelength used for the experiment. The range of wavelengths used was
0.48–7.0 Angstroms, BUT the bulk of the diffraction information is obtained
from wavelengths in the range 0.7–2.5 Angstroms. The data-collection
procedures on the SXD instrument used for the single-crystal neutron data
collection are most recently summarized in the Appendix to the following paper:
Wilson, C.C. (1997). J. Mol. Struct. 405, 207–217 |
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. The variable wavelength nature of the data-collection procedure means that
sensible values of _diffrn_reflns_theta_min and _diffrn_reflns_theta_max cannot
be given. Instead, the following limits are given
_diffrn_reflns_sin(theta)/lambda_min 0.08
_diffrn_reflns_sin(theta)/lambda_max 1.38
_refine_diff_density_max/min is given in Fermi per per angstrom cubed not
electrons per angstrom cubed. Another way to consider the _refine_diff_density_
is as a percentage of the scattering density of a given atom:
_refine_diff_density_max = 3% of oxygen
_refine_diff_density_min = -3% of oxygen
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Mg1 | 1.0000 | 0.0000 | 0.0000 | 0.0031 (5) | |
OW1 | 0.6591 (3) | 0.1751 (4) | 0.00642 (11) | 0.0070 (4) | |
H1A | 0.5558 (7) | 0.2382 (10) | 0.0478 (3) | 0.0242 (11) | |
H1B | 0.5686 (7) | 0.1860 (9) | −0.0386 (3) | 0.0206 (9) | |
OW2 | 0.9837 (3) | −0.2640 (4) | 0.05091 (11) | 0.0062 (4) | |
H2A | 1.1062 (7) | −0.4002 (9) | 0.0673 (3) | 0.0228 (10) | |
H2B | 0.8512 (7) | −0.2622 (9) | 0.0740 (3) | 0.0202 (9) | |
OW3 | 1.0464 (3) | 0.1017 (4) | 0.10562 (11) | 0.0067 (4) | |
H3A | 1.0425 (8) | 0.0365 (9) | 0.1555 (2) | 0.0216 (9) | |
H3B | 1.1223 (8) | 0.1903 (10) | 0.1096 (3) | 0.0232 (10) | |
Mg2 | 1.0000 | 0.0000 | 0.5000 | 0.0040 (5) | |
OW4 | 1.1484 (3) | −0.1033 (4) | 0.39480 (11) | 0.0062 (4) | |
H4A | 1.2979 (6) | −0.1184 (9) | 0.3850 (3) | 0.0189 (9) | |
H4B | 1.0780 (7) | −0.0798 (9) | 0.3443 (2) | 0.0197 (9) | |
OW5 | 0.8066 (3) | −0.1528 (4) | 0.48574 (11) | 0.0069 (4) | |
H5A | 0.7719 (8) | −0.2393 (9) | 0.5234 (3) | 0.0209 (9) | |
H5B | 0.7144 (7) | −0.1370 (9) | 0.4409 (2) | 0.0189 (9) | |
OW6 | 0.7564 (3) | 0.2810 (4) | 0.44853 (11) | 0.0056 (4) | |
H6A | 0.7983 (7) | 0.3341 (9) | 0.4012 (3) | 0.0208 (9) | |
H6B | 0.6015 (6) | 0.3156 (9) | 0.4411 (3) | 0.0208 (10) | |
Cr1 | 0.4078 (4) | 0.3200 (6) | 0.20166 (15) | 0.0022 (5) | |
O1 | 0.3001 (3) | 0.3376 (4) | 0.11601 (10) | 0.0051 (3) | |
O2 | 0.2081 (3) | 0.4569 (4) | 0.26429 (11) | 0.0060 (3) | |
O3 | 0.5424 (3) | 0.0602 (4) | 0.22978 (11) | 0.0059 (4) | |
O4 | 0.5838 (3) | 0.4215 (4) | 0.19749 (11) | 0.0062 (4) | |
OW7 | 0.3116 (3) | 0.4086 (4) | 0.41912 (11) | 0.0062 (4) | |
H7A | 0.2786 (7) | 0.4262 (10) | 0.3644 (2) | 0.0221 (10) | |
H7B | 0.2406 (9) | 0.5530 (10) | 0.4380 (4) | 0.0276 (11) | |
OW8 | 0.6070 (3) | −0.2410 (4) | 0.11869 (12) | 0.0069 (4) | |
H8A | 0.5670 (8) | −0.1290 (9) | 0.1576 (3) | 0.0207 (8) | |
H8B | 0.6039 (8) | −0.3656 (9) | 0.1452 (3) | 0.0210 (9) | |
OW9 | 0.5608 (3) | −0.1510 (4) | 0.36308 (11) | 0.0064 (4) | |
H9A | 0.5411 (7) | −0.0546 (9) | 0.3179 (2) | 0.0204 (9) | |
H9B | 0.6573 (7) | −0.2973 (8) | 0.3446 (3) | 0.0196 (9) | |
OW10 | 0.8338 (3) | 0.4416 (4) | 0.31354 (11) | 0.0070 (4) | |
H10A | 0.7579 (7) | 0.4168 (10) | 0.2706 (3) | 0.0213 (9) | |
H10B | 0.9740 (6) | 0.4303 (9) | 0.2930 (3) | 0.0210 (9) | |
OW11 | 0.9964 (3) | −0.0875 (4) | 0.24672 (11) | 0.0061 (4) | |
H11A | 1.0639 (8) | −0.2447 (9) | 0.2448 (3) | 0.0225 (9) | |
H11B | 0.8371 (6) | −0.0362 (9) | 0.2411 (3) | 0.0224 (10) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Mg1 | 0.0024 (8) | 0.0037 (13) | 0.0036 (9) | −0.0018 (8) | 0.0000 (7) | 0.0003 (9) |
OW1 | 0.0038 (5) | 0.0096 (10) | 0.0058 (7) | −0.0016 (6) | 0.0005 (5) | −0.0002 (7) |
H1A | 0.0193 (17) | 0.030 (3) | 0.0160 (17) | −0.0044 (18) | 0.0077 (13) | −0.0074 (17) |
H1B | 0.0166 (15) | 0.027 (3) | 0.0164 (16) | −0.0083 (16) | −0.0042 (13) | −0.0008 (16) |
OW2 | 0.0055 (6) | 0.0056 (9) | 0.0082 (7) | −0.0033 (6) | −0.0010 (5) | 0.0026 (7) |
H2A | 0.0158 (15) | 0.016 (2) | 0.030 (2) | −0.0019 (16) | −0.0044 (15) | 0.0075 (19) |
H2B | 0.0152 (14) | 0.022 (2) | 0.0236 (19) | −0.0084 (16) | 0.0052 (13) | 0.0009 (17) |
OW3 | 0.0073 (6) | 0.0089 (10) | 0.0053 (7) | −0.0050 (7) | −0.0003 (5) | 0.0002 (7) |
H3A | 0.030 (2) | 0.026 (3) | 0.0123 (15) | −0.016 (2) | 0.0019 (14) | 0.0045 (16) |
H3B | 0.029 (2) | 0.025 (3) | 0.026 (2) | −0.021 (2) | −0.0023 (17) | 0.0004 (19) |
Mg2 | 0.0034 (8) | 0.0053 (13) | 0.0029 (9) | −0.0016 (9) | −0.0001 (7) | −0.0002 (9) |
OW4 | 0.0043 (6) | 0.0087 (10) | 0.0052 (6) | −0.0027 (6) | 0.0009 (5) | −0.0010 (6) |
H4A | 0.0133 (13) | 0.025 (2) | 0.0208 (17) | −0.0109 (16) | 0.0021 (12) | −0.0002 (17) |
H4B | 0.0197 (15) | 0.027 (3) | 0.0138 (15) | −0.0120 (17) | −0.0054 (13) | 0.0008 (16) |
OW5 | 0.0092 (7) | 0.0098 (10) | 0.0054 (6) | −0.0077 (7) | −0.0014 (5) | 0.0008 (7) |
H5A | 0.0269 (18) | 0.027 (3) | 0.0179 (17) | −0.0203 (19) | −0.0013 (14) | 0.0037 (17) |
H5B | 0.0204 (16) | 0.024 (2) | 0.0158 (16) | −0.0128 (17) | −0.0057 (13) | 0.0018 (16) |
OW6 | 0.0053 (6) | 0.0045 (9) | 0.0064 (7) | −0.0016 (6) | −0.0003 (5) | 0.0018 (6) |
H6A | 0.0191 (15) | 0.025 (2) | 0.0179 (16) | −0.0105 (17) | 0.0018 (13) | 0.0084 (17) |
H6B | 0.0109 (13) | 0.027 (3) | 0.0235 (19) | −0.0081 (16) | −0.0021 (13) | 0.0017 (18) |
Cr1 | 0.0033 (8) | 0.0025 (13) | 0.0019 (9) | −0.0023 (9) | −0.0007 (7) | 0.0006 (9) |
O1 | 0.0045 (6) | 0.0077 (10) | 0.0025 (6) | −0.0023 (6) | −0.0009 (5) | 0.0004 (6) |
O2 | 0.0044 (6) | 0.0060 (9) | 0.0055 (6) | −0.0006 (6) | 0.0017 (5) | −0.0015 (6) |
O3 | 0.0050 (6) | 0.0048 (9) | 0.0057 (7) | −0.0004 (6) | −0.0003 (5) | 0.0018 (6) |
O4 | 0.0056 (6) | 0.0082 (10) | 0.0067 (7) | −0.0049 (7) | −0.0005 (5) | 0.0007 (7) |
OW7 | 0.0055 (6) | 0.0070 (10) | 0.0056 (6) | −0.0026 (6) | 0.0004 (5) | 0.0003 (6) |
H7A | 0.0236 (17) | 0.029 (3) | 0.0120 (15) | −0.0112 (19) | −0.0011 (13) | 0.0031 (16) |
H7B | 0.026 (2) | 0.014 (3) | 0.039 (3) | −0.0056 (19) | 0.0035 (19) | −0.010 (2) |
OW8 | 0.0067 (6) | 0.0082 (10) | 0.0066 (7) | −0.0043 (7) | −0.0001 (5) | 0.0012 (7) |
H8A | 0.028 (2) | 0.018 (2) | 0.0192 (18) | −0.0136 (18) | 0.0047 (15) | −0.0074 (16) |
H8B | 0.030 (2) | 0.018 (2) | 0.0181 (17) | −0.0143 (18) | −0.0001 (15) | 0.0036 (17) |
OW9 | 0.0059 (6) | 0.0078 (10) | 0.0053 (6) | −0.0030 (6) | −0.0001 (5) | 0.0001 (6) |
H9A | 0.0220 (16) | 0.022 (2) | 0.0148 (16) | −0.0085 (17) | −0.0011 (13) | 0.0074 (16) |
H9B | 0.0191 (16) | 0.012 (2) | 0.025 (2) | −0.0048 (15) | 0.0031 (14) | −0.0023 (17) |
OW10 | 0.0067 (6) | 0.0096 (10) | 0.0055 (6) | −0.0045 (7) | 0.0002 (5) | 0.0002 (7) |
H10A | 0.0220 (17) | 0.031 (3) | 0.0155 (16) | −0.0161 (19) | −0.0007 (14) | −0.0065 (17) |
H10B | 0.0132 (13) | 0.028 (3) | 0.0219 (18) | −0.0099 (17) | 0.0047 (13) | −0.0022 (18) |
OW11 | 0.0048 (6) | 0.0067 (10) | 0.0059 (7) | −0.0017 (6) | 0.0009 (5) | −0.0010 (6) |
H11A | 0.0214 (17) | 0.012 (2) | 0.030 (2) | −0.0036 (16) | 0.0012 (16) | −0.0023 (18) |
H11B | 0.0110 (13) | 0.024 (3) | 0.029 (2) | −0.0053 (15) | −0.0031 (14) | 0.003 (2) |
Geometric parameters (Å, º) top
Mg1—OW2i | 2.053 (2) | OW4—H4B | 0.977 (4) |
Mg1—OW2 | 2.053 (2) | OW5—H5A | 0.972 (5) |
Mg1—OW1i | 2.0622 (19) | OW5—H5B | 0.977 (4) |
Mg1—OW1 | 2.0622 (19) | OW6—H6A | 0.983 (4) |
Mg1—OW3i | 2.066 (2) | OW6—H6B | 0.972 (4) |
Mg1—OW3 | 2.066 (2) | Cr1—O4 | 1.637 (4) |
OW1—H1A | 0.964 (5) | Cr1—O1 | 1.643 (3) |
OW1—H1B | 0.980 (5) | Cr1—O3 | 1.660 (4) |
OW2—H2A | 0.965 (5) | Cr1—O2 | 1.667 (4) |
OW2—H2B | 0.974 (4) | OW7—H7A | 0.971 (5) |
OW3—H3A | 0.972 (4) | OW7—H7B | 0.957 (7) |
OW3—H3B | 0.967 (6) | OW8—H8A | 0.985 (6) |
Mg2—OW5 | 2.045 (2) | OW8—H8B | 0.974 (5) |
Mg2—OW5ii | 2.045 (2) | OW9—H9A | 0.984 (4) |
Mg2—OW4 | 2.065 (2) | OW9—H9B | 0.982 (6) |
Mg2—OW4ii | 2.065 (2) | OW10—H10A | 0.973 (5) |
Mg2—OW6ii | 2.071 (2) | OW10—H10B | 0.981 (4) |
Mg2—OW6 | 2.071 (2) | OW11—H11A | 0.969 (6) |
OW4—H4A | 0.983 (4) | OW11—H11B | 0.975 (4) |
| | | |
OW2i—Mg1—OW2 | 179.999 (1) | OW5—Mg2—OW6ii | 89.89 (9) |
OW2i—Mg1—OW1i | 89.78 (8) | OW5ii—Mg2—OW6ii | 90.11 (9) |
OW2—Mg1—OW1i | 90.22 (8) | OW4—Mg2—OW6ii | 89.43 (8) |
OW2i—Mg1—OW1 | 90.22 (8) | OW4ii—Mg2—OW6ii | 90.57 (8) |
OW2—Mg1—OW1 | 89.78 (8) | OW5—Mg2—OW6 | 90.11 (9) |
OW1i—Mg1—OW1 | 180.0 | OW5ii—Mg2—OW6 | 89.89 (9) |
OW2i—Mg1—OW3i | 90.97 (9) | OW4—Mg2—OW6 | 90.57 (8) |
OW2—Mg1—OW3i | 89.03 (9) | OW4ii—Mg2—OW6 | 89.43 (8) |
OW1i—Mg1—OW3i | 92.78 (9) | OW6ii—Mg2—OW6 | 180.0 |
OW1—Mg1—OW3i | 87.22 (9) | Mg2—OW4—H4A | 120.0 (3) |
OW2i—Mg1—OW3 | 89.03 (9) | Mg2—OW4—H4B | 128.5 (3) |
OW2—Mg1—OW3 | 90.97 (9) | H4A—OW4—H4B | 105.5 (4) |
OW1i—Mg1—OW3 | 87.22 (9) | Mg2—OW5—H5A | 128.0 (3) |
OW1—Mg1—OW3 | 92.78 (9) | Mg2—OW5—H5B | 125.8 (3) |
OW3i—Mg1—OW3 | 179.999 (1) | H5A—OW5—H5B | 105.7 (4) |
Mg1—OW1—H1A | 134.3 (3) | Mg2—OW6—H6A | 116.6 (3) |
Mg1—OW1—H1B | 119.2 (3) | Mg2—OW6—H6B | 126.4 (4) |
H1A—OW1—H1B | 105.8 (4) | H6A—OW6—H6B | 105.1 (4) |
Mg1—OW2—H2A | 127.3 (3) | O4—Cr1—O1 | 109.39 (17) |
Mg1—OW2—H2B | 125.1 (3) | O4—Cr1—O3 | 108.85 (17) |
H2A—OW2—H2B | 106.1 (4) | O1—Cr1—O3 | 109.2 (2) |
Mg1—OW3—H3A | 126.5 (4) | O4—Cr1—O2 | 109.5 (2) |
Mg1—OW3—H3B | 120.6 (3) | O1—Cr1—O2 | 110.17 (17) |
H3A—OW3—H3B | 110.1 (5) | O3—Cr1—O2 | 109.79 (18) |
OW5—Mg2—OW5ii | 180.0 | H7A—OW7—H7B | 104.8 (5) |
OW5—Mg2—OW4 | 91.04 (9) | H8A—OW8—H8B | 105.6 (5) |
OW5ii—Mg2—OW4 | 88.96 (9) | H9A—OW9—H9B | 104.0 (5) |
OW5—Mg2—OW4ii | 88.96 (9) | H10A—OW10—H10B | 106.1 (4) |
OW5ii—Mg2—OW4ii | 91.03 (9) | H11A—OW11—H11B | 106.1 (5) |
OW4—Mg2—OW4ii | 180.0 | | |
Symmetry codes: (i) −x+2, −y, −z; (ii) −x+2, −y, −z+1. |
Comparison of interatomic distances (Å) and angles (°) in the coordination
polyhedra (X = S1 or Cr1), including calculated polyhedral volumes
(Å3), between MgSO4.11H2O and MgCrO4.11H2O top | MgSO4.11H2O | MgCrO4.11H2O |
| | |
Mg1—OW1 | 2.0566 (9) | 2.062 (2) |
Mg1—OW2 | 2.0617 (11) | 2.053 (2) |
Mg1—OW3 | 2.0794 (10) | 2.066 (2) |
Volume of M1 (Å3) | 11.743 (5) | 11.648 (12) |
| | |
Mg2—OW4 | 2.0767 (10) | 2.065 (2) |
Mg2—OW5 | 2.0458 (9) | 2.045 (2) |
Mg2—OW6 | 2.0699 (11) | 2.071 (2) |
Volume of M2 (Å3) | 11.722 (6) | 11.657 (12) |
| | |
X—O1 | 1.467 (2) | 1.643 (3) |
X—O2 | 1.473 (2) | 1.667 (4) |
X—O3 | 1.486 (2) | 1.660 (4) |
X—O4 | 1.488 (2) | 1.637 (4) |
Volume of T1 (Å3) | 1.656 (1) | 2.312 (4) |
| | |
OW1—Mg1—OW2 | 89.36 (4) | 89.78 (8) |
OW1—Mg1—OW3 | 92.58 (4) | 92.78 (9) |
OW2—Mg1—OW3 | 90.06 (4) | 90.97 (9) |
| | |
OW4—Mg2—OW5 | 90.75 (4) | 91.04 (9) |
OW4—Mg2—OW6 | 90.23 (4) | 90.57 (8) |
OW5—Mg2—OW6 | 89.93 (4) | 90.11 (9) |
| | |
O1—X—O2 | 110.0 (1) | 110.2 (2) |
O1—X—O3 | 108.8 (1) | 109.2 (2) |
O1—X—O4 | 110.3 (1) | 109.4 (2) |
O2—X—O3 | 108.6 (1) | 109.8 (2) |
O2—X—O4 | 109.7 (1) | 109.5 (2) |
O3—X—O4 | 109.3 (1) | 108.9 (2) |
Polyhedral volumes computed using Cayley–Menger determinants (Wirth &
Dreiding, 2009). |
Comparison of distances (Å) and angles (°) pertaining to the hydrogen-bond
geometry in MgSO4.11H2O (upper half) and MgCrO4.11H2O (lower half) topMgSO4.11H2O | | | | |
| D—H | H···A | D···A | D—H···A |
OW1—H1A···O1 | 0.964 (2) | 1.893 (2) | 2.8406 (14) | 167.1 (2) |
OW1—H1B···OW8i | 0.975 (3) | 1.764 (3) | 2.7363 (16) | 174.0 (2) |
OW2—H2A···O1ii | 0.965 (2) | 1.861 (3) | 2.8124 (15) | 168.2 (3) |
OW2—H2B···OW8 | 0.974 (2) | 1.783 (2) | 2.7526 (14) | 173.8 (2) |
OW3—H3A···OW11 | 0.965 (3) | 1.893 (3) | 2.8505 (17) | 171.3 (2) |
OW3—H3B···O1iii | 0.972 (2) | 1.882 (2) | 2.8520 (12) | 175.5 (3) |
OW4—H4A···OW9iii | 0.981 (2) | 1.731 (2) | 2.7108 (13) | 176.6 (2) |
OW4—H4B···OW11 | 0.980 (3) | 1.793 (3) | 2.7603 (16) | 168.4 (2) |
OW5—H5A···OW7i | 0.977 (3) | 1.774 (3) | 2.7461 (16) | 173.2 (3) |
OW5—H5B···OW9 | 0.978 (3) | 1.755 (3) | 2.7283 (15) | 173.0 (2) |
OW6—H6A···OW10 | 0.976 (3) | 1.753 (3) | 2.7212 (17) | 170.6 (2) |
OW6—H6B···OW7 | 0.975 (2) | 1.815 (2) | 2.7825 (14) | 171.5 (3) |
OW7—H7A···O2 | 0.978 (3) | 1.813 (3) | 2.7888 (16) | 175.0 (2) |
OW7—H7B···OW4iv | 0.966 (2) | 2.096 (3) | 2.9558 (15) | 147.4 (3) |
OW7—H7B···OW6v | 0.966 (2) | 2.484 (3) | 3.1694 (14) | 127.7 (3) |
OW8—H8A···O3 | 0.973 (2) | 1.857 (2) | 2.8176 (13) | 168.7 (2) |
OW8—H8B···O4vi | 0.975 (3) | 1.780 (3) | 2.7526 (15) | 175.1 (2) |
OW9—H9A···O3 | 0.984 (3) | 1.737 (3) | 2.7036 (16) | 166.4 (2) |
OW9—H9B···OW10vi | 0.983 (2) | 1.749 (2) | 2.7310 (13) | 177.0 (3) |
OW10—H10A···O4 | 0.983 (2) | 1.718 (2) | 2.6877 (15) | 168.4 (2) |
OW10—H10B···O2iii | 0.970 (2) | 1.797 (2) | 2.7455 (13) | 165.1 (2) |
OW11—H11A···O2ii | 0.975 (2) | 1.881 (2) | 2.8359 (14) | 165.3 (3) |
OW11—H11B···O3 | 0.975 (2) | 1.834 (2) | 2.8095 (14) | 178.3 (2) |
| | | | |
MgCrO4.11H2O | | | | |
OW1—H1A···O1 | 0.964 (5) | 1.950 (5) | 2.891 (3) | 164.7 (5) |
OW1—H1B···OW8i | 0.980 (5) | 1.757 (4) | 2.732 (3) | 172.8 (6) |
OW2—H2A···O1ii | 0.965 (5) | 1.865 (5) | 2.814 (3) | 167.4 (5) |
OW2—H2B···OW8 | 0.974 (4) | 1.767 (4) | 2.740 (3) | 175.9 (6) |
OW3—H3A···OW11 | 0.972 (4) | 1.872 (4) | 2.837 (3) | 171.7 (4) |
OW3—H3B···O1iii | 0.967 (6) | 1.907 (5) | 2.870 (3) | 174.0 (5) |
OW4—H4A···OW9iii | 0.983 (4) | 1.730 (4) | 2.712 (3) | 176.9 (5) |
OW4—H4B···OW11 | 0.977 (4) | 1.801 (5) | 2.766 (3) | 168.4 (5) |
OW5—H5A···OW7i | 0.972 (5) | 1.792 (5) | 2.757 (3) | 171.2 (5) |
OW5—H5B···OW9 | 0.977 (4) | 1.747 (5) | 2.717 (3) | 171.2 (5) |
OW6—H6A···OW10 | 0.983 (4) | 1.740 (4) | 2.716 (3) | 172.0 (4) |
OW6—H6B···OW7 | 0.972 (4) | 1.805 (4) | 2.772 (3) | 172.5 (5) |
OW7—H7A···O2 | 0.971 (5) | 1.793 (5) | 2.763 (3) | 177.7 (5) |
OW7—H7B···OW4iv | 0.957 (7) | 2.269 (6) | 3.050 (4) | 138.3 (5) |
OW7—H7B···OW6v | 0.957 (7) | 2.320 (7) | 3.085 (4) | 136.4 (5) |
OW8—H8A···O3 | 0.985 (6) | 1.794 (6) | 2.770 (4) | 170.6 (4) |
OW8—H8B···O4vi | 0.974 (5) | 1.764 (5) | 2.737 (3) | 176.0 (5) |
OW9—H9A···O3 | 0.984 (4) | 1.708 (4) | 2.676 (3) | 167.3 (5) |
OW9—H9B···OW10vi | 0.982 (6) | 1.748 (6) | 2.731 (4) | 178.6 (5) |
OW10—H10A···O4 | 0.973 (5) | 1.734 (5) | 2.696 (3) | 169.2 (5) |
OW10—H10B···O2iii | 0.981 (4) | 1.744 (5) | 2.714 (3) | 169.3 (6) |
OW11—H11A···O2ii | 0.969 (6) | 1.857 (6) | 2.810 (3) | 167.1 (5) |
OW11—H11B···O3 | 0.975 (4) | 1.802 (4) | 2.777 (3) | 179.4 (5) |
See Fig. 3 for a graphical representation of these data.
Symmetry codes: (i) -x + 1, -y, -z;
(ii) x + 1, y - 1, z;
(iii) x + 1, y, z;
(iv) x - 1, y + 1, z;
(v) -x + 1, -y + 1, -z + 1;
(vi) x, y - 1, z. |
Principal axis magnitudes of the elastic strain tensor, and the corresponding
direction cosines, computed from the change in unit-cell parameters on
substitution of CrVI for SVI in MgSO4.11H2O. See Fig. 5 for a
graphical representation of this information. top | This work, | 5–10 K | | | Fortes & Wood (2012), | 258 K | | |
| Strain | Direction | cosines | | Strain | Direction | cosines | |
ε1 | 0.67 (7) % | 0.9648 | -0.0658 | -0.3150 | 0.885 (6) % | 0.9780 | -0.1675 | -0.1244 |
ε2 | 2.20 (9) % | 0.0748 | 0.9971 | 0.0166 | 2.182 (5) % | 0.1837 | 0.9739 | 0.1331 |
ε3 | 0.43 (7)% | 0.3130 | -0.0392 | 0.9489 | 0.458 (6) % | 0.0989 | -0.1530 | 0.9833 |
εV | 3.30 (14) % | | | | 3.53 (1) % | | | |
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