Crystal structures of sodium magnesium selenate deca­hydrate, Na₂Mg(SeO₄)₂·10H₂O, a new selenate salt, and sodium magnesium selenate dihydrate, Na₂Mg(SeO₄)₂·2H₂O

Metal selenates crystallize in many instances in isomorphic structures of the corresponding sulfates. Sodium magnesium selenate deca­hydrate, Na₂Mg(SeO₄)₂·10H₂O, and sodium magnesium selenate dihydrate, Na₂Mg(SeO₄)₂·2H₂O, were synthesized by preparing solutions of Na₂SeO₄ and MgSeO₄·6H₂O with different molar ratios. The structures contain different Mg octa­hedra, i.e. [Mg(H₂O)₆] octa­hedra in the deca­hydrate and [MgO₄(H₂O)₂] octa­hedra in the dihydrate. The sodium polyhedra are also different, i.e. [NaO₂(H₂O)₄] in the deca­hydrate and [NaO₆(H₂O)] in the dihydrate. The selenate tetra­hedra are connected with the chains of Na polyhedra in the two structures. O—H...O hydrogen bonding is observed in both structures between the coordinating water mol­ecules and selenate O atoms.

Computing details

For both compounds, data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg, 2012); software used to prepare material for publication: publCIF (Westrip, 2010).

(Na2_Seo4_Mg_Seo4_10H2O) Disodium magnesium bis(selenate) decahydrate

Crystal data

Na2Mg(SeO4)2·10H2O	F(000) = 532
Mr = 536.37	Dx = 2.161 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 12.671 (2) Å	Cell parameters from 8438 reflections
b = 6.610 (1) Å	θ = 3.4–29.2°
c = 10.2706 (2) Å	µ = 4.66 mm^−1
β = 106.64 (1)°	T = 150 K
V = 824.2 (3) Å^3	Plate, colorless
Z = 2	0.5 × 0.3 × 0.1 mm

Data collection

Stoe IPDS 2T diffractometer	2196 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1923 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.037
Detector resolution: 6.67 pixels mm^-1	θmax = 29.2°, θmin = 3.4°
rotation method scans	h = −17→13
Absorption correction: integration (Coppens & Hamilton, 1970)	k = −9→9
Tmin = 0.139, Tmax = 0.298	l = −14→14
8438 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.020	All H-atom parameters refined
wR(F^2) = 0.046	w = 1/[σ^2(Fo^2) + (0.017P)^2 + 0.8734P] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max = 0.001
2196 reflections	Δρmax = 0.34 e Å^−3
146 parameters	Δρmin = −0.52 e Å^−3

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
Mg1	1.000000	0.500000	1.000000	0.01252 (16)
Na1	0.51950 (6)	0.25556 (11)	0.59730 (8)	0.01698 (15)
Se1	0.72146 (2)	0.01411 (2)	0.83122 (2)	0.01166 (6)
O1	0.78600 (11)	−0.0030 (2)	0.99550 (13)	0.0166 (3)
O2	0.79807 (11)	−0.0827 (2)	0.74047 (13)	0.0165 (3)
O3	0.69661 (11)	0.25347 (19)	0.78934 (13)	0.0175 (3)
O4	0.60491 (12)	−0.1082 (2)	0.79357 (14)	0.0208 (3)
O5	0.38548 (12)	−0.0320 (2)	0.52315 (15)	0.0197 (3)
H5A	0.333 (3)	0.020 (5)	0.470 (3)	0.041 (9)*
H5B	0.366 (3)	−0.090 (5)	0.585 (3)	0.040 (8)*
O6	0.40053 (13)	0.4096 (2)	0.39924 (14)	0.0176 (3)
H6A	0.394 (3)	0.327 (5)	0.338 (3)	0.043 (9)*
H6B	0.343 (3)	0.419 (5)	0.413 (3)	0.032 (8)*
O7	0.86250 (12)	0.5371 (2)	0.83744 (14)	0.0188 (3)
H7A	0.838 (2)	0.649 (5)	0.794 (3)	0.033 (7)*
H7B	0.812 (3)	0.454 (5)	0.812 (3)	0.039 (8)*
O8	1.08770 (12)	0.6626 (2)	0.88585 (14)	0.0163 (3)
H8A	1.120 (2)	0.758 (5)	0.918 (3)	0.031 (8)*
H8B	1.128 (3)	0.591 (6)	0.853 (3)	0.048 (9)*
O9	1.02763 (12)	0.2364 (2)	0.90905 (14)	0.0175 (3)
H9A	1.083 (2)	0.174 (5)	0.936 (3)	0.030 (7)*
H9B	1.003 (3)	0.218 (5)	0.827 (3)	0.045 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mg1	0.0149 (4)	0.0103 (4)	0.0122 (4)	0.0009 (3)	0.0037 (3)	0.0006 (3)
Na1	0.0178 (4)	0.0160 (3)	0.0169 (3)	0.0014 (3)	0.0047 (3)	−0.0006 (3)
Se1	0.01403 (8)	0.00992 (8)	0.01125 (8)	0.00030 (6)	0.00395 (6)	−0.00004 (6)
O1	0.0191 (6)	0.0159 (6)	0.0136 (5)	0.0013 (5)	0.0028 (5)	0.0009 (5)
O2	0.0205 (6)	0.0135 (6)	0.0182 (6)	0.0019 (5)	0.0098 (5)	0.0010 (5)
O3	0.0214 (7)	0.0114 (6)	0.0186 (6)	0.0034 (5)	0.0039 (5)	0.0014 (5)
O4	0.0206 (7)	0.0245 (7)	0.0187 (6)	−0.0069 (6)	0.0077 (5)	−0.0054 (5)
O5	0.0221 (7)	0.0197 (7)	0.0181 (6)	−0.0015 (6)	0.0072 (6)	0.0027 (5)
O6	0.0190 (7)	0.0171 (6)	0.0161 (6)	−0.0013 (5)	0.0041 (5)	−0.0020 (5)
O7	0.0183 (6)	0.0132 (6)	0.0206 (6)	0.0005 (5)	−0.0011 (5)	0.0035 (5)
O8	0.0191 (7)	0.0130 (6)	0.0180 (6)	−0.0019 (5)	0.0073 (5)	−0.0023 (5)
O9	0.0200 (7)	0.0155 (6)	0.0154 (6)	0.0050 (5)	0.0023 (5)	−0.0029 (5)

Geometric parameters (Å, º)

Mg1—O9^i	2.0541 (14)	Na1—O5	2.5173 (18)
Mg1—O9	2.0541 (14)	Na1—O3	2.5280 (15)
Mg1—O7	2.0535 (14)	Na1—Se1	3.3683 (9)
Mg1—O7^i	2.0535 (14)	Na1—Na1^iii	3.7572 (18)
Mg1—O8^i	2.1238 (14)	Na1—Na1^iv	3.8844 (18)
Mg1—O8	2.1238 (14)	Se1—O4	1.6301 (14)
Na1—O4^ii	2.3590 (16)	Se1—O3	1.6462 (14)
Na1—O6	2.3855 (16)	Se1—O2	1.6551 (13)
Na1—O6^iii	2.4302 (18)	Se1—O1	1.6547 (13)
Na1—O5^iv	2.4529 (17)
O9^i—Mg1—O9	180.0	O5^iv—Na1—Se1	72.06 (4)
O9^i—Mg1—O7	93.04 (6)	O5—Na1—Se1	99.60 (5)
O9—Mg1—O7	86.96 (6)	O3—Na1—Se1	28.08 (3)
O9^i—Mg1—O7^i	86.96 (6)	O4^ii—Na1—Na1^iii	85.44 (5)
O9—Mg1—O7^i	93.04 (6)	O6—Na1—Na1^iii	39.15 (4)
O7—Mg1—O7^i	180.00 (8)	O6^iii—Na1—Na1^iii	38.30 (4)
O9^i—Mg1—O8^i	89.65 (6)	O5^iv—Na1—Na1^iii	104.99 (5)
O9—Mg1—O8^i	90.35 (6)	O5—Na1—Na1^iii	120.93 (5)
O7—Mg1—O8^i	93.04 (6)	O3—Na1—Na1^iii	111.83 (5)
O7^i—Mg1—O8^i	86.96 (6)	Se1—Na1—Na1^iii	138.10 (4)
O9^i—Mg1—O8	90.35 (6)	O4^ii—Na1—Na1^iv	124.93 (5)
O9—Mg1—O8	89.65 (6)	O6—Na1—Na1^iv	88.65 (5)
O7—Mg1—O8	86.96 (6)	O6^iii—Na1—Na1^iv	142.26 (5)
O7^i—Mg1—O8	93.04 (6)	O5^iv—Na1—Na1^iv	39.19 (4)
O8^i—Mg1—O8	180.0	O5—Na1—Na1^iv	38.01 (4)
O4^ii—Na1—O6	84.10 (6)	O3—Na1—Na1^iv	110.51 (5)
O4^ii—Na1—O6^iii	88.74 (6)	Se1—Na1—Na1^iv	85.04 (3)
O6—Na1—O6^iii	77.45 (6)	Na1^iii—Na1—Na1^iv	119.77 (4)
O4^ii—Na1—O5^iv	163.93 (6)	O4—Se1—O3	108.81 (7)
O6—Na1—O5^iv	96.24 (6)	O4—Se1—O2	108.19 (7)
O6^iii—Na1—O5^iv	107.05 (6)	O3—Se1—O2	108.89 (7)
O4^ii—Na1—O5	86.98 (6)	O4—Se1—O1	110.95 (7)
O6—Na1—O5	81.82 (6)	O3—Se1—O1	109.51 (7)
O6^iii—Na1—O5	159.15 (6)	O2—Se1—O1	110.45 (7)
O5^iv—Na1—O5	77.20 (6)	O4—Se1—Na1	67.32 (6)
O4^ii—Na1—O3	101.31 (5)	O3—Se1—Na1	46.28 (5)
O6—Na1—O3	150.52 (6)	O2—Se1—Na1	103.29 (5)
O6^iii—Na1—O3	73.76 (5)	O1—Se1—Na1	144.33 (5)
O5^iv—Na1—O3	86.33 (5)	Se1—O3—Na1	105.65 (7)
O5—Na1—O3	127.09 (6)	Se1—O4—Na1^v	139.46 (8)
O4^ii—Na1—Se1	108.45 (4)	Na1^iv—O5—Na1	102.80 (6)
O6—Na1—Se1	167.40 (5)	Na1—O6—Na1^iii	102.55 (6)
O6^iii—Na1—Se1	101.11 (4)

Symmetry codes: (i) −x+2, −y+1, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iii) −x+1, −y+1, −z+1; (iv) −x+1, −y, −z+1; (v) −x+1, y−1/2, −z+3/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O9—H9B···O8^vi	0.82 (3)	2.19 (3)	3.002 (2)	170 (3)
O9—H9A···O1^vii	0.79 (3)	1.97 (3)	2.755 (2)	176 (3)
O9—H9A···Se1^vii	0.79 (3)	3.17 (3)	3.8868 (15)	153 (2)
O8—H8B···O2^viii	0.83 (4)	1.91 (4)	2.736 (2)	172 (3)
O8—H8B···Se1^viii	0.83 (4)	3.09 (3)	3.8561 (15)	154 (3)
O8—H8A···O1^i	0.77 (3)	2.06 (3)	2.827 (2)	176 (3)
O8—H8A···Se1^i	0.77 (3)	3.16 (3)	3.8515 (15)	151 (3)
O7—H7B···O3	0.83 (3)	1.93 (3)	2.754 (2)	169 (3)
O7—H7B···Se1	0.83 (3)	3.15 (3)	3.8837 (18)	149 (3)
O7—H7A···O2^ix	0.87 (3)	1.88 (3)	2.740 (2)	167 (3)
O7—H7A···Se1^ix	0.87 (3)	2.91 (3)	3.6162 (17)	139 (2)
O6—H6B···O1^ii	0.78 (3)	2.17 (3)	2.925 (2)	162 (3)
O6—H6B···Se1^ii	0.78 (3)	3.04 (3)	3.6030 (16)	132 (2)
O6—H6A···O4^iv	0.82 (3)	1.98 (3)	2.796 (2)	172 (3)
O6—H6A···Se1^iv	0.82 (3)	2.96 (3)	3.7070 (16)	151 (3)
O5—H5B···O3^v	0.84 (3)	1.99 (3)	2.819 (2)	172 (3)
O5—H5B···Se1^v	0.84 (3)	3.06 (3)	3.7730 (17)	145 (3)
O5—H5A···O2^iv	0.80 (3)	2.36 (3)	3.116 (2)	158 (3)
O5—H5A···Se1^iv	0.80 (3)	2.98 (3)	3.5031 (15)	125 (3)

Symmetry codes: (i) −x+2, −y+1, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iv) −x+1, −y, −z+1; (v) −x+1, y−1/2, −z+3/2; (vi) −x+2, y−1/2, −z+3/2; (vii) −x+2, −y, −z+2; (viii) −x+2, y+1/2, −z+3/2; (ix) x, y+1, z.

(Mg_SeO4_Na2_SeO4_2H2O) Disodium magnesium bis(selenate) dihydrate

Crystal data

Na2Mg(SeO4)2·2H2O	Z = 1
Mr = 392.24	F(000) = 186
Triclinic, P1	Dx = 3.102 Mg m^−3
a = 5.556 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 5.923 (4) Å	Cell parameters from 3582 reflections
c = 7.224 (5) Å	θ = 3.0–29.6°
α = 108.36 (6)°	µ = 9.12 mm^−1
β = 99.07 (5)°	T = 200 K
γ = 106.63 (6)°	Prism, colourless
V = 208.0 (3) Å^3	0.20 × 0.10 × 0.05 mm

Data collection

Stoe IPDS 2T diffractometer	864 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	782 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.062
Detector resolution: 6.67 pixels mm^-1	θmax = 26.5°, θmin = 3.9°
rotation method scans	h = −6→6
Absorption correction: integration (Coppens & Hamilton, 1970)	k = −7→7
Tmin = 0.398, Tmax = 0.584	l = −5→9
3328 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.032	All H-atom parameters refined
wR(F^2) = 0.084	w = 1/[σ^2(Fo^2) + (0.0149P)^2 + 1.464P] where P = (Fo^2 + 2Fc^2)/3
S = 1.27	(Δ/σ)max < 0.001
864 reflections	Δρmax = 0.92 e Å^−3
79 parameters	Δρmin = −0.74 e Å^−3

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.

Refinement. Refined as a 2-component inversion twin.

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

	x	y	z	Uiso*/Ueq
Se1	0.33844 (11)	0.16724 (12)	0.25986 (9)	0.0128 (2)
Mg1	0.0000	0.5000	0.5000	0.0138 (6)
O5	−0.0653 (9)	0.5420 (10)	0.2307 (7)	0.0160 (9)
O4	0.2829 (8)	−0.1330 (8)	0.1244 (7)	0.0176 (9)
O2	0.1053 (8)	0.1752 (9)	0.3768 (7)	0.0183 (9)
O3	0.3541 (8)	0.3371 (9)	0.1210 (7)	0.0182 (9)
O1	0.6138 (8)	0.2620 (9)	0.4357 (7)	0.0189 (9)
Na1	0.6657 (5)	0.7902 (5)	0.2476 (4)	0.0234 (6)
H5A	0.06 (2)	0.63 (2)	0.210 (15)	0.04 (3)*
H5B	−0.125 (16)	0.412 (18)	0.133 (14)	0.03 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Se1	0.0094 (3)	0.0159 (3)	0.0131 (3)	0.0045 (2)	0.0032 (2)	0.0054 (2)
Mg1	0.0115 (13)	0.0181 (15)	0.0120 (14)	0.0052 (11)	0.0026 (11)	0.0063 (12)
O5	0.013 (2)	0.017 (2)	0.013 (2)	0.0016 (18)	0.0009 (18)	0.004 (2)
O4	0.018 (2)	0.017 (2)	0.016 (2)	0.0076 (18)	0.0060 (17)	0.0026 (19)
O2	0.015 (2)	0.020 (2)	0.024 (2)	0.0087 (18)	0.0101 (18)	0.008 (2)
O3	0.017 (2)	0.025 (2)	0.019 (2)	0.0090 (19)	0.0056 (18)	0.014 (2)
O1	0.0113 (19)	0.022 (2)	0.021 (2)	0.0026 (17)	0.0007 (17)	0.010 (2)
Na1	0.0193 (12)	0.0256 (14)	0.0284 (15)	0.0111 (11)	0.0055 (11)	0.0120 (12)

Geometric parameters (Å, º)

Se1—O3	1.625 (4)	O2—Na1^ii	2.727 (6)
Se1—O4	1.646 (5)	O3—Na1^vi	2.503 (6)
Se1—O1	1.648 (5)	O3—Na1	2.516 (6)
Se1—O2	1.658 (4)	O1—Mg1^vii	2.086 (5)
Mg1—O5	2.028 (5)	O1—Na1^iv	2.816 (6)
Mg1—O5^i	2.028 (5)	O1—Na1^ii	3.006 (6)
Mg1—O1^ii	2.086 (5)	Na1—O5^vii	2.369 (5)
Mg1—O1^iii	2.086 (5)	Na1—O4^viii	2.395 (5)
Mg1—O2^i	2.137 (5)	Na1—O3^vi	2.503 (6)
Mg1—O2	2.137 (5)	Na1—O2^ix	2.605 (6)
O5—Na1^iii	2.369 (5)	Na1—O2^ii	2.727 (6)
O4—Na1^iv	2.395 (5)	Na1—O1^viii	2.816 (6)
O2—Na1^v	2.605 (6)	Na1—O1^ii	3.006 (6)
O3—Se1—O4	111.7 (2)	Se1—O1—Na1^iv	89.4 (2)
O3—Se1—O1	112.7 (2)	Mg1^vii—O1—Na1^iv	98.82 (18)
O4—Se1—O1	105.0 (2)	Se1—O1—Na1^ii	92.55 (19)
O3—Se1—O2	112.0 (2)	Mg1^vii—O1—Na1^ii	124.2 (2)
O4—Se1—O2	107.9 (2)	Na1^iv—O1—Na1^ii	106.92 (16)
O1—Se1—O2	107.2 (2)	O5^vii—Na1—O4^viii	153.0 (2)
O3—Se1—Na1^iv	122.77 (17)	O5^vii—Na1—O3^vi	81.18 (18)
O4—Se1—Na1^iv	45.27 (17)	O4^viii—Na1—O3^vi	79.65 (17)
O1—Se1—Na1^iv	60.10 (18)	O5^vii—Na1—O3	74.98 (18)
O2—Se1—Na1^iv	124.52 (17)	O4^viii—Na1—O3	83.35 (18)
O3—Se1—Na1^ii	141.16 (18)	O3^vi—Na1—O3	81.05 (19)
O4—Se1—Na1^ii	106.91 (18)	O5^vii—Na1—O2^ix	84.57 (19)
O1—Se1—Na1^ii	59.32 (17)	O4^viii—Na1—O2^ix	116.24 (19)
O2—Se1—Na1^ii	49.60 (17)	O3^vi—Na1—O2^ix	96.15 (19)
Na1^iv—Se1—Na1^ii	87.86 (9)	O3—Na1—O2^ix	159.56 (18)
O5—Mg1—O5^i	180.0 (3)	O5^vii—Na1—O2^ii	68.51 (17)
O5—Mg1—O1^ii	87.64 (19)	O4^viii—Na1—O2^ii	131.32 (18)
O5^i—Mg1—O1^ii	92.36 (19)	O3^vi—Na1—O2^ii	148.83 (17)
O5—Mg1—O1^iii	92.36 (19)	O3—Na1—O2^ii	97.35 (18)
O5^i—Mg1—O1^iii	87.64 (19)	O2^ix—Na1—O2^ii	74.55 (18)
O1^ii—Mg1—O1^iii	180.0	O5^vii—Na1—O1^viii	147.3 (2)
O5—Mg1—O2^i	87.59 (19)	O4^viii—Na1—O1^viii	59.56 (16)
O5^i—Mg1—O2^i	92.41 (19)	O3^vi—Na1—O1^viii	116.08 (17)
O1^ii—Mg1—O2^i	90.13 (19)	O3—Na1—O1^viii	132.60 (17)
O1^iii—Mg1—O2^i	89.87 (19)	O2^ix—Na1—O1^viii	66.79 (16)
O5—Mg1—O2	92.41 (19)	O2^ii—Na1—O1^viii	88.01 (17)
O5^i—Mg1—O2	87.59 (19)	O5^vii—Na1—O1^ii	107.89 (17)
O1^ii—Mg1—O2	89.87 (19)	O4^viii—Na1—O1^ii	79.80 (16)
O1^iii—Mg1—O2	90.13 (19)	O3^vi—Na1—O1^ii	147.73 (18)
O2^i—Mg1—O2	180.0	O3—Na1—O1^ii	72.08 (16)
O5—Mg1—Na1^ii	139.98 (14)	O2^ix—Na1—O1^ii	115.23 (18)
O5^i—Mg1—Na1^ii	40.02 (14)	O2^ii—Na1—O1^ii	55.05 (14)
O1^ii—Mg1—Na1^ii	79.00 (14)	O1^viii—Na1—O1^ii	73.08 (16)
O1^iii—Mg1—Na1^ii	101.00 (14)	O5^vii—Na1—Se1^viii	174.58 (16)
O2^i—Mg1—Na1^ii	129.49 (14)	O4^viii—Na1—Se1^viii	29.24 (12)
O2—Mg1—Na1^ii	50.51 (14)	O3^vi—Na1—Se1^viii	96.43 (14)
O5—Mg1—Na1^iii	40.02 (14)	O3—Na1—Se1^viii	109.55 (14)
O5^i—Mg1—Na1^iii	139.98 (14)	O2^ix—Na1—Se1^viii	90.87 (14)
O1^ii—Mg1—Na1^iii	101.00 (14)	O2^ii—Na1—Se1^viii	113.11 (14)
O1^iii—Mg1—Na1^iii	79.00 (14)	O1^viii—Na1—Se1^viii	30.48 (10)
O2^i—Mg1—Na1^iii	50.51 (14)	O1^ii—Na1—Se1^viii	76.71 (11)
O2—Mg1—Na1^iii	129.49 (14)	O5^vii—Na1—Se1^ii	90.95 (14)
Na1^ii—Mg1—Na1^iii	180.00 (8)	O4^viii—Na1—Se1^ii	104.52 (15)
O5—Mg1—Na1^x	88.22 (17)	O3^vi—Na1—Se1^ii	168.06 (15)
O5^i—Mg1—Na1^x	91.78 (17)	O3—Na1—Se1^ii	88.26 (15)
O1^ii—Mg1—Na1^x	47.87 (15)	O2^ix—Na1—Se1^ii	92.01 (15)
O1^iii—Mg1—Na1^x	132.13 (15)	O2^ii—Na1—Se1^ii	27.59 (9)
O2^i—Mg1—Na1^x	42.31 (13)	O1^viii—Na1—Se1^ii	75.20 (13)
O2—Mg1—Na1^x	137.69 (13)	O1^ii—Na1—Se1^ii	28.13 (9)
Na1^ii—Mg1—Na1^x	108.80 (11)	Se1^viii—Na1—Se1^ii	92.14 (9)
Na1^iii—Mg1—Na1^x	71.20 (11)	O5^vii—Na1—Mg1^vii	33.40 (12)
O5—Mg1—Na1^v	91.78 (17)	O4^viii—Na1—Mg1^vii	152.72 (15)
O5^i—Mg1—Na1^v	88.22 (17)	O3^vi—Na1—Mg1^vii	114.13 (14)
O1^ii—Mg1—Na1^v	132.13 (15)	O3—Na1—Mg1^vii	76.21 (14)
O1^iii—Mg1—Na1^v	47.87 (15)	O2^ix—Na1—Mg1^vii	86.70 (14)
O2^i—Mg1—Na1^v	137.69 (13)	O2^ii—Na1—Mg1^vii	37.21 (10)
O2—Mg1—Na1^v	42.31 (13)	O1^viii—Na1—Mg1^vii	124.80 (14)
Na1^ii—Mg1—Na1^v	71.20 (11)	O1^ii—Na1—Mg1^vii	76.85 (11)
Na1^iii—Mg1—Na1^v	108.80 (11)	Se1^viii—Na1—Mg1^vii	149.43 (10)
Na1^x—Mg1—Na1^v	180.0	Se1^ii—Na1—Mg1^vii	57.55 (6)
Mg1—O5—Na1^iii	106.6 (2)	O5^vii—Na1—Mg1^ix	116.97 (16)
Se1—O4—Na1^iv	105.5 (2)	O4^viii—Na1—Mg1^ix	87.17 (15)
Se1—O2—Mg1	125.5 (2)	O3^vi—Na1—Mg1^ix	108.15 (15)
Se1—O2—Na1^v	120.8 (2)	O3—Na1—Mg1^ix	165.42 (14)
Mg1—O2—Na1^v	104.18 (18)	O2^ix—Na1—Mg1^ix	33.51 (11)
Se1—O2—Na1^ii	102.8 (2)	O2^ii—Na1—Mg1^ix	80.66 (14)
Mg1—O2—Na1^ii	92.28 (18)	O1^viii—Na1—Mg1^ix	33.31 (10)
Na1^v—O2—Na1^ii	105.45 (18)	O1^ii—Na1—Mg1^ix	95.37 (13)
Se1—O3—Na1^vi	129.3 (3)	Se1^viii—Na1—Mg1^ix	59.05 (8)
Se1—O3—Na1	122.3 (2)	Se1^ii—Na1—Mg1^ix	83.40 (10)
Na1^vi—O3—Na1	98.95 (19)	Mg1^vii—Na1—Mg1^ix	108.80 (11)
Se1—O1—Mg1^vii	137.0 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5B···O4^xi	0.80 (10)	1.92 (10)	2.709 (7)	171 (8)
O5—H5A···O4^viii	0.81 (11)	1.93 (11)	2.703 (7)	161 (9)

Symmetry codes: (viii) x, y+1, z; (xi) −x, −y, −z.