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The lithium terbium polyphosphate LiTb(PO3)4 was prepared by the flux method using a large excess of H3PO4. It was structurally characterized by single-crystal X-ray diffraction and found to be isotypic with LiYb(PO3)4. The basic structural units are endless spiral chains, (PO3)n, along the b-axis direction. The Li+ and Tb3+ cations alternate on twofold axes and are four- and eight-coordinated, respectively. The results of an optical study of this material are also given and discussed.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536806051737/br2021sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536806051737/br2021Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](P-O) = 0.003 Å
  • R factor = 0.020
  • wR factor = 0.054
  • Data-to-parameter ratio = 11.6

checkCIF/PLATON results

No syntax errors found



Alert level C CRYSC01_ALERT_1_C The word below has not been recognised as a standard identifier. colouless CRYSC01_ALERT_1_C No recognised colour has been given for crystal colour. PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.77 PLAT153_ALERT_1_C The su's on the Cell Axes are Equal (x 100000) . 200 Ang.
Alert level G ABSTM02_ALERT_3_G When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.773 Tmax scaled 0.500 Tmin scaled 0.182 PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Computing details top

Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97.

lithium terbium polyphosphate top
Crystal data top
LiTb(PO3)4F(000) = 896
Mr = 481.74Dx = 3.569 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71069 Å
Hall symbol: -C 2ycCell parameters from 25 reflections
a = 16.358 (2) Åθ = 10.7–14.7°
b = 7.050 (2) ŵ = 8.67 mm1
c = 9.629 (2) ÅT = 293 K
β = 126.15 (1)°Plate, colourless
V = 896.7 (4) Å30.28 × 0.16 × 0.08 mm
Z = 4
Data collection top
Enraf–Nonius CAD-4
diffractometer
951 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.016
Graphite monochromatorθmax = 26.9°, θmin = 3.1°
ω/2θ scansh = 2017
Absorption correction: ψ scan
(North et al., 1968)
k = 18
Tmin = 0.236, Tmax = 0.646l = 112
1324 measured reflections2 standard reflections every 120 min
974 independent reflections intensity decay: 1%
Refinement top
Refinement on F2Primary atom site location: heavy-atom method
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.020 w = 1/[σ2(Fo2) + (0.0344P)2 + 5.8217P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.054(Δ/σ)max < 0.001
S = 1.08Δρmax = 1.38 e Å3
974 reflectionsΔρmin = 1.15 e Å3
84 parametersExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0025 (2)
Special details top

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. 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
xyzUiso*/Ueq
Li0.00000.705 (1)0.25000.018 (2)
Tb0.00000.20252 (3)0.25000.0065 (1)
P10.13795 (7)0.5530 (1)0.6151 (1)0.0064 (2)
P20.14715 (7)0.1520 (1)0.6974 (1)0.0068 (2)
O10.1137 (2)0.7167 (4)0.6825 (4)0.0121 (6)
O20.0719 (2)0.0871 (4)0.7268 (4)0.0106 (5)
O30.1286 (2)0.1149 (4)0.5286 (3)0.0116 (5)
O40.1578 (2)0.3762 (4)0.7340 (3)0.0108 (5)
O50.2555 (2)0.0801 (4)0.8536 (3)0.0104 (5)
O60.0653 (2)0.5027 (4)0.4280 (3)0.0097 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Li0.024 (6)0.016 (6)0.016 (5)0.0000.013 (5)0.000
Tb0.0053 (2)0.0071 (2)0.0066 (2)0.0000.0031 (1)0.000
P10.0045 (4)0.0069 (5)0.0069 (4)0.0004 (3)0.0029 (4)0.0002 (3)
P20.0047 (4)0.0079 (4)0.0075 (4)0.0000 (3)0.0035 (4)0.0011 (3)
O10.011 (1)0.012 (1)0.016 (1)0.000 (1)0.009 (1)0.003 (1)
O20.006 (1)0.011 (1)0.017 (1)0.000 (1)0.008 (1)0.002 (1)
O30.012 (1)0.012 (1)0.009 (1)0.001 (1)0.005 (1)0.000 (1)
O40.016 (1)0.007 (1)0.010 (1)0.000 (1)0.008 (1)0.000 (1)
O50.006 (1)0.016 (1)0.010 (1)0.001 (1)0.005 (1)0.002 (1)
O60.005 (1)0.012 (1)0.008 (1)0.002 (1)0.002 (1)0.000 (1)
Geometric parameters (Å, º) top
Li—O2i1.974 (8)Tb—O2vi2.432 (3)
Li—O2ii1.974 (8)Tb—O62.530 (3)
Li—O6iii1.987 (7)Tb—O6iii2.530 (3)
Li—O61.987 (7)P1—O11.488 (3)
Li—Tbiv3.509 (10)P1—O61.502 (3)
Li—Tb3.541 (10)P1—O41.591 (3)
Tb—O3iii2.312 (3)P1—O5vii1.596 (3)
Tb—O32.312 (3)P2—O21.488 (3)
Tb—O1i2.374 (3)P2—O31.490 (3)
Tb—O1ii2.374 (3)P2—O51.586 (3)
Tb—O2v2.432 (3)P2—O41.606 (3)
O2i—Li—O2ii84.0 (4)O6—P1—O5vii105.0 (1)
O2i—Li—O6iii119.23 (11)O4—P1—O5vii102.8 (1)
O2ii—Li—O6iii125.26 (11)O2—P2—O3119.6 (2)
O2i—Li—O6125.26 (11)O2—P2—O5107.9 (1)
O2ii—Li—O6119.23 (11)O3—P2—O5111.9 (2)
O6iii—Li—O688.4 (4)O2—P2—O4104.8 (1)
O1—P1—O6118.7 (2)O3—P2—O4109.8 (1)
O1—P1—O4106.7 (2)O5—P2—O4101.0 (2)
O6—P1—O4111.1 (1)P1—O4—P2131.5 (2)
O1—P1—O5vii111.5 (2)P2—O5—P1viii134.6 (2)
Symmetry codes: (i) x, y+1, z1/2; (ii) x, y+1, z+1; (iii) x, y, z+1/2; (iv) x, y+1, z; (v) x, y, z+1; (vi) x, y, z1/2; (vii) x+1/2, y+1/2, z+3/2; (viii) x+1/2, y1/2, z+3/2.
 

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