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The crystal structure of monoclinic KGd(WO4)2 (KGW) has been refined at room temperature by using single-crystal X-ray diffraction data. The unit-cell parameters are a = 10.652 (4), b = 10.374 (6), c = 7.582 (2) Å, β = 130.80 (2)°, with Z = 4, in space group C2/c. The linear thermal expansion tensor has been determined and the principal axes are [302], [010] and [106]. The principal axis with maximum thermal expansion (\boldalpha'_{33} = 23.44 × 10−6 K−1), {\bf X}'_{3}, was located 12° from the c axis. Undoped crystals of KGW and crystals that were partially doped by Pr, Nd, Ho, Er, Tm and Yb were grown by the top-seeding-solution growth slow-cooling method. The effect of doping on the KGW structure was observed in the cell parameters and in morphological changes. The changes in parameters follow the changes in lanthanide ionic radii. The doped crystals show {021} and {\bar{2}21} faces in addition to the {110}, {\bar{1}11}, {010}, {130} and {310} faces which basically follow the habit of the undoped KGW crystals. The development of the faces is related to the number of the most important periodic bond chains parallel to them.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889800013352/os0053sup1.cif
Contains datablock mag27c

sft

Structure factor file (SHELXL table format) https://doi.org/10.1107/S0021889800013352/os0053sup2.sft
Supplementary material

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S0021889800013352/os0053sup3.pdf
Anisotropic displacement parameters

Computing details top

Program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL93 (Sheldrick, 1993).

Gadollinium potassium wolframate top
Crystal data top
GdKO8W2F(000) = 1180
Mr = 692.05Dx = 7.248 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71069 Å
a = 10.652 (4) ÅCell parameters from 25 reflections
b = 10.374 (6) Åθ = 12–21°
c = 7.582 (2) ŵ = 47.18 mm1
β = 130.80 (2)°T = 293 K
V = 634.2 (5) Å3Sphere, colourless
Z = 40.4 mm (radius)
Data collection top
Enraf-Nonius CAD-4
diffractometer
865 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.000
Graphite monochromatorθmax = 29.9°, θmin = 3.2°
ω–2θ scansh = 1411
Absorption correction: sphericalk = 014
l = 010
926 measured reflections3 standard reflections every 120 min
926 independent reflections intensity decay: none
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullPrimary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.053Secondary atom site location: difference Fourier map
wR(F2) = 0.193Calculated w = 1/[σ2(Fo2) + (0.1088P)2 + 6.2657P] P = (Fo2 + 2Fc2)/3
S = 1.11Δρmax = 0.59 e Å3
876 reflectionsΔρmin = 0.84 e Å3
56 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Gd0.00000.72769 (6)0.25000.0133 (2)
W0.19491 (4)0.00007 (3)0.73586 (6)0.0131 (2)
K0.50000.2000 (3)0.75000.0166 (5)
O10.3726 (14)0.0741 (12)0.8106 (18)0.046 (2)
O20.0258 (14)0.1090 (12)0.4713 (17)0.045 (2)
O30.2690 (13)0.1593 (12)0.8686 (17)0.045 (2)
O40.1905 (14)0.0749 (12)0.9381 (18)0.044 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Gd0.0148 (4)0.0130 (4)0.0138 (3)0.0000.0101 (3)0.000
W0.0148 (4)0.0127 (3)0.0137 (3)0.00005 (9)0.0101 (3)0.00021 (9)
K0.0178 (13)0.0175 (11)0.0159 (11)0.0000.0117 (11)0.000
O10.060 (7)0.039 (5)0.048 (5)0.003 (5)0.039 (5)0.003 (5)
O20.056 (6)0.040 (5)0.046 (5)0.001 (4)0.036 (5)0.001 (4)
O30.051 (6)0.044 (5)0.044 (5)0.001 (5)0.033 (5)0.000 (4)
O40.055 (6)0.044 (5)0.043 (4)0.002 (5)0.037 (5)0.000 (5)
Geometric parameters (Å, º) top
W—O41.747 (10)W—K3.798 (2)
W—O11.758 (12)Gd—Kv3.8018 (10)
W—O31.825 (12)Gd—Kxv3.8018 (10)
W—O21.955 (11)Gd—O2xvi2.271 (12)
W—O2i2.109 (11)Gd—O1xvii2.325 (12)
W—O4ii2.359 (9)Gd—O3viii2.371 (10)
Gd—O2iii2.271 (12)Gd—O3xviii2.650 (11)
Gd—O1iv2.325 (12)Gd—Wvi3.5492 (15)
Gd—O3v2.371 (10)Gd—Wxviii3.5492 (15)
Gd—O3vi2.650 (11)K—O4viii2.796 (13)
K—O4vii2.796 (13)K—O4xix2.821 (12)
K—O4ii2.821 (12)K—O1xix2.956 (11)
K—O1ii2.956 (11)K—O2vii3.038 (12)
K—O2viii3.038 (12)K—O3xx3.152 (11)
K—O33.152 (11)K—O1xx3.309 (12)
K—O13.309 (12)O1—Gdiv2.325 (12)
W—Wi3.260 (3)O1—Kxix2.956 (11)
W—Wii3.791 (2)O2—Wi2.109 (11)
W—Wix3.791 (2)O2—Gdxiii2.271 (12)
W—Gdx3.549 (2)O2—Kxiv3.038 (12)
W—Gdxi3.845 (2)O3—Gdxi2.371 (10)
W—Gdxii3.961 (2)O3—Gdxviii2.650 (11)
W—Gdxiii3.983 (2)O4—Wix2.359 (9)
W—Kix3.675 (2)O4—Kxiv2.796 (13)
W—Kxiv3.780 (3)O4—Kxix2.821 (12)
O2iii—Gd—O2xvi83.5 (6)Kxix—W—Kxiv68.09 (4)
O2iii—Gd—O1iv148.5 (4)O4—W—K137.0 (4)
O2xvi—Gd—O1iv99.8 (4)O1—W—K60.6 (4)
O2iii—Gd—O1xvii99.8 (4)O3—W—K55.7 (3)
O2xvi—Gd—O1xvii148.5 (4)O2—W—K122.8 (3)
O1iv—Gd—O1xvii93.5 (6)O2i—W—K104.2 (3)
O2iii—Gd—O3v130.7 (4)O4ii—W—K47.8 (3)
O2xvi—Gd—O3v78.1 (4)Gdxviii—W—K94.05 (6)
O1iv—Gd—O3v80.1 (4)Kxix—W—K97.54 (6)
O1xvii—Gd—O3v76.2 (4)Kxiv—W—K157.60 (7)
O2iii—Gd—O3viii78.1 (4)O4vii—K—O4viii66.8 (5)
O2xvi—Gd—O3viii130.7 (4)O4vii—K—O4ii150.8 (3)
O1iv—Gd—O3viii76.2 (4)O4viii—K—O4ii84.0 (4)
O1xvii—Gd—O3viii80.1 (4)O4vii—K—O4xix84.0 (4)
O3v—Gd—O3viii145.2 (6)O4viii—K—O4xix150.8 (3)
O2iii—Gd—O3vi80.6 (4)O4ii—K—O4xix125.2 (5)
O2xvi—Gd—O3vi60.2 (4)O4vii—K—O1ii126.1 (3)
O1iv—Gd—O3vi74.3 (4)O4viii—K—O1ii98.5 (3)
O1xvii—Gd—O3vi151.3 (4)O4ii—K—O1ii55.1 (3)
O3v—Gd—O3vi125.2 (4)O4xix—K—O1ii99.5 (3)
O3viii—Gd—O3vi71.8 (4)O4vii—K—O1xix98.5 (3)
O2iii—Gd—O3xviii60.2 (4)O4viii—K—O1xix126.1 (3)
O2xvi—Gd—O3xviii80.6 (4)O4ii—K—O1xix99.5 (3)
O1iv—Gd—O3xviii151.3 (4)O4xix—K—O1xix55.1 (3)
O1xvii—Gd—O3xviii74.3 (4)O1ii—K—O1xix127.5 (5)
O3v—Gd—O3xviii71.8 (4)O4vii—K—O2viii57.7 (3)
O3viii—Gd—O3xviii125.2 (4)O4viii—K—O2viii56.3 (3)
O3vi—Gd—O3xviii127.5 (5)O4ii—K—O2viii107.2 (3)
O2iii—Gd—Wvi68.7 (3)O4xix—K—O2viii107.7 (3)
O2xvi—Gd—Wvi34.4 (3)O1ii—K—O2viii152.7 (3)
O1iv—Gd—Wvi96.4 (3)O1xix—K—O2viii71.8 (3)
O1xvii—Gd—Wvi168.5 (3)O4vii—K—O2vii56.3 (3)
O3v—Gd—Wvi111.3 (3)O4viii—K—O2vii57.7 (3)
O3viii—Gd—Wvi96.5 (3)O4ii—K—O2vii107.7 (3)
O3vi—Gd—Wvi30.0 (2)O4xix—K—O2vii107.2 (3)
O3xviii—Gd—Wvi99.3 (3)O1ii—K—O2vii71.8 (3)
O2iii—Gd—Wxviii34.4 (3)O1xix—K—O2vii152.7 (3)
O2xvi—Gd—Wxviii68.7 (3)O2viii—K—O2vii98.6 (5)
O1iv—Gd—Wxviii168.5 (3)O4vii—K—O3114.1 (3)
O1xvii—Gd—Wxviii96.4 (3)O4viii—K—O379.4 (3)
O3v—Gd—Wxviii96.5 (3)O4ii—K—O358.3 (3)
O3viii—Gd—Wxviii111.3 (3)O4xix—K—O3113.7 (3)
O3vi—Gd—Wxviii99.3 (3)O1ii—K—O3113.2 (3)
O3xviii—Gd—Wxviii30.0 (3)O1xix—K—O359.2 (3)
Wvi—Gd—Wxviii74.48 (4)O2viii—K—O356.4 (3)
O2iii—Gd—Kv135.6 (3)O2vii—K—O3136.8 (3)
O2xvi—Gd—Kv53.0 (3)O4vii—K—O3xx79.4 (3)
O1iv—Gd—Kv51.0 (3)O4viii—K—O3xx114.1 (3)
O1xvii—Gd—Kv121.7 (3)O4ii—K—O3xx113.7 (3)
O3v—Gd—Kv55.8 (3)O4xix—K—O3xx58.3 (3)
O3viii—Gd—Kv121.2 (3)O1ii—K—O3xx59.2 (3)
O3vi—Gd—Kv70.6 (2)O1xix—K—O3xx113.2 (3)
O3xviii—Gd—Kv113.5 (2)O2viii—K—O3xx136.8 (3)
Wvi—Gd—Kv69.44 (5)O2vii—K—O3xx56.4 (3)
Wxviii—Gd—Kv118.12 (5)O3—K—O3xx164.6 (5)
O2iii—Gd—Kxv53.0 (3)O4vii—K—O1150.8 (3)
O2xvi—Gd—Kxv135.6 (3)O4viii—K—O1124.2 (3)
O1iv—Gd—Kxv121.7 (3)O4ii—K—O150.3 (3)
O1xvii—Gd—Kxv51.0 (3)O4xix—K—O181.3 (3)
O3v—Gd—Kxv121.2 (3)O1ii—K—O181.3 (2)
O3viii—Gd—Kxv55.8 (3)O1xix—K—O152.5 (4)
O3vi—Gd—Kxv113.5 (2)O2viii—K—O1103.4 (3)
O3xviii—Gd—Kxv70.6 (2)O2vii—K—O1152.7 (3)
Wvi—Gd—Kxv118.12 (5)O3—K—O151.5 (3)
Wxviii—Gd—Kxv69.44 (5)O3xx—K—O1113.1 (3)
Kv—Gd—Kxv171.34 (10)O4vii—K—O1xx124.2 (3)
O4—W—O199.4 (5)O4viii—K—O1xx150.8 (3)
O4—W—O399.7 (5)O4ii—K—O1xx81.3 (3)
O1—W—O3103.4 (5)O4xix—K—O1xx50.3 (3)
O4—W—O296.2 (5)O1ii—K—O1xx52.5 (4)
O1—W—O298.9 (5)O1xix—K—O1xx81.3 (2)
O3—W—O2150.0 (5)O2viii—K—O1xx152.7 (3)
O4—W—O2i103.6 (5)O2vii—K—O1xx103.4 (3)
O1—W—O2i156.3 (5)O3—K—O1xx113.1 (3)
O3—W—O2i78.1 (5)O3xx—K—O1xx51.5 (3)
O2—W—O2i73.4 (6)O1—K—O1xx61.5 (4)
O4—W—O4ii172.6 (3)W—O1—Gdiv151.6 (6)
O1—W—O4ii78.3 (5)W—O1—Kxix99.3 (4)
O3—W—O4ii87.7 (4)Gdiv—O1—Kxix91.3 (4)
O2—W—O4ii77.3 (4)W—O1—K91.9 (4)
O2i—W—O4ii78.2 (4)Gdiv—O1—K102.5 (4)
O4—W—Gdxviii88.6 (4)Kxix—O1—K127.5 (4)
O1—W—Gdxviii149.9 (4)W—O2—Wi106.6 (6)
O3—W—Gdxviii46.6 (3)W—O2—Gdxiii140.8 (6)
O2—W—Gdxviii109.0 (4)Wi—O2—Gdxiii108.2 (4)
O2i—W—Gdxviii37.4 (3)W—O2—Kxiv96.0 (4)
O4ii—W—Gdxviii96.9 (3)Wi—O2—Kxiv107.7 (4)
O4—W—Kxix47.9 (4)Gdxiii—O2—Kxiv90.3 (4)
O1—W—Kxix52.6 (3)W—O3—Gdxi132.4 (6)
O3—W—Kxix99.3 (3)W—O3—Gdxviii103.4 (4)
O2—W—Kxix110.2 (3)Gdxi—O3—Gdxviii108.2 (4)
O2i—W—Kxix151.1 (3)W—O3—K95.8 (4)
O4ii—W—Kxix130.7 (3)Gdxi—O3—K85.8 (3)
Gdxviii—W—Kxix123.14 (4)Gdxviii—O3—K135.8 (4)
O4—W—Kxiv43.8 (4)W—O4—Wix134.3 (7)
O1—W—Kxiv97.3 (4)W—O4—Kxiv110.5 (5)
O3—W—Kxiv141.0 (3)Wix—O4—Kxiv108.5 (4)
O2—W—Kxiv53.0 (3)W—O4—Kxix104.7 (5)
O2i—W—Kxiv95.6 (3)Wix—O4—Kxix93.9 (3)
O4ii—W—Kxiv129.1 (3)Kxiv—O4—Kxix96.0 (4)
Gdxviii—W—Kxiv108.14 (5)
Symmetry codes: (i) x, y, z+1; (ii) x, y, z1/2; (iii) x, y+1, z; (iv) x+1/2, y+1/2, z+1; (v) x1/2, y+1/2, z1; (vi) x, y+1, z1/2; (vii) x+1/2, y+1/2, z; (viii) x+1/2, y+1/2, z+3/2; (ix) x, y, z+1/2; (x) x, y+1, z+1/2; (xi) x+1/2, y1/2, z+1; (xii) x+1/2, y+1/2, z+1/2; (xiii) x, y1, z; (xiv) x1/2, y1/2, z; (xv) x1/2, y+1/2, z; (xvi) x, y+1, z+1/2; (xvii) x1/2, y+1/2, z1/2; (xviii) x, y+1, z+1; (xix) x+1, y, z+2; (xx) x+1, y, z+3/2.
 

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