The crystal structure of a new CdTe₂O₅ polymorph, isotypic with [epsilon]-CaTe₂O₅

The crystal structure of a new polymorph of CdTe₂O₅, designated as the β-form, contains ²_∞[Te₂O₅]^2– (100) layers with an undulating shape.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](Cd-O) = 0.003 Å
• R factor = 0.024
• wR factor = 0.045
• Data-to-parameter ratio = 25.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT975_ALERT_2_C Check Calcd Resid. Dens.  0.67A   From O3              0.93 eA-3
PLAT975_ALERT_2_C Check Calcd Resid. Dens.  0.66A   From O2              0.77 eA-3
PLAT976_ALERT_2_C Check Calcd Resid. Dens.  1.06A   From O5             -0.75 eA-3

Alert level G
PLAT004_ALERT_5_G Polymeric Structure Found with Maximum Dimension          3 Info
PLAT395_ALERT_2_G Deviating  X-O-Y    Angle From 120 for O5             103.5 Degree
PLAT432_ALERT_2_G Short Inter X...Y Contact  Te2      ..O1               3.09 Ang.
                                             x,3/2-y,-1/2+z  =      4_575 Check
PLAT794_ALERT_5_G Tentative Bond Valency for Cd1       (II)      .       2.19 Info
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Theta(Min).          1 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   3 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   5 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
   0 ALERT type 4 Improvement, methodology, query or suggestion
   2 ALERT type 5 Informative message, check

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Computing details

Data collection: APEX3 (Bruker, 2016); cell refinement: SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: ATOMS (Dowty, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Cadmium pentaoxidoditellurate(IV)

Crystal data

CdTe2O5	F(000) = 768
Mr = 447.60	Dx = 5.699 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.4535 (5) Å	Cell parameters from 2645 reflections
b = 5.5806 (3) Å	θ = 2.4–32.1°
c = 10.8607 (5) Å	µ = 15.08 mm^−1
β = 114.430 (1)°	T = 100 K
V = 521.67 (5) Å^3	Block, colourless
Z = 4	0.10 × 0.06 × 0.05 mm

Data collection

Bruker APEXII CCD diffractometer	1462 reflections with I > 2σ(I)
ω– and φ–scan	Rint = 0.045
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	θmax = 32.1°, θmin = 3.8°
Tmin = 0.600, Tmax = 0.746	h = −14→14
9236 measured reflections	k = −8→8
1827 independent reflections	l = −15→16

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: isomorphous structure methods
R[F^2 > 2σ(F^2)] = 0.024	w = 1/[σ^2(Fo^2) + (0.0171P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.045	(Δ/σ)max = 0.001
S = 1.00	Δρmax = 1.20 e Å^−3
1827 reflections	Δρmin = −1.03 e Å^−3
73 parameters

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
Te1	0.25911 (3)	0.32034 (5)	0.72297 (3)	0.01195 (7)
Te2	0.34935 (3)	0.64780 (5)	0.49078 (3)	0.01181 (7)
Cd1	0.01900 (4)	0.79762 (6)	0.63620 (3)	0.01416 (8)
O1	0.1293 (4)	0.4948 (5)	0.7821 (3)	0.0141 (6)
O2	0.1216 (4)	0.1359 (5)	0.5843 (3)	0.0188 (7)
O3	0.2239 (4)	0.5960 (5)	0.5973 (3)	0.0163 (7)
O4	0.2081 (4)	0.0287 (6)	0.8466 (3)	0.0162 (7)
O5	0.4791 (4)	0.3979 (6)	0.5962 (3)	0.0176 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Te1	0.00997 (13)	0.01304 (14)	0.01191 (13)	0.00123 (10)	0.00360 (10)	−0.00069 (10)
Te2	0.01214 (13)	0.01187 (13)	0.01070 (13)	−0.00178 (10)	0.00399 (10)	−0.00077 (10)
Cd1	0.01824 (16)	0.01311 (16)	0.01254 (15)	0.00370 (12)	0.00778 (13)	0.00255 (12)
O1	0.0171 (16)	0.0124 (15)	0.0175 (15)	0.0035 (12)	0.0116 (13)	0.0054 (12)
O2	0.0256 (18)	0.0146 (16)	0.0109 (15)	−0.0055 (14)	0.0023 (13)	−0.0008 (13)
O3	0.0199 (17)	0.0142 (15)	0.0209 (16)	0.0035 (13)	0.0144 (14)	0.0032 (13)
O4	0.0162 (16)	0.0142 (15)	0.0159 (15)	0.0016 (13)	0.0044 (13)	0.0068 (13)
O5	0.0162 (16)	0.0198 (16)	0.0188 (16)	0.0060 (13)	0.0094 (13)	0.0072 (13)

Geometric parameters (Å, º)

Te1—O2	1.843 (3)	Te2—Te2^ii	3.2253 (6)
Te1—O1	1.875 (3)	Cd1—O1^iii	2.235 (3)
Te1—O3	1.991 (3)	Cd1—O2^iv	2.238 (3)
Te1—O4	2.285 (3)	Cd1—O2^v	2.296 (3)
Te2—O4^i	1.864 (3)	Cd1—O1	2.255 (3)
Te2—O5	1.897 (3)	Cd1—O3	2.424 (3)
Te2—O3	1.990 (3)	Cd1—O4^v	2.589 (3)
Te2—O5^ii	2.204 (3)	Cd1—O4^iii	2.688 (3)
O2—Te1—O1	103.25 (15)	O1^iii—Cd1—O3	167.39 (11)
O2—Te1—O3	90.59 (13)	O2^iv—Cd1—O3	93.09 (12)
O1—Te1—O3	83.46 (12)	O2^v—Cd1—O3	83.66 (11)
O2—Te1—O4	80.40 (12)	O1—Cd1—O3	66.67 (10)
O1—Te1—O4	80.89 (12)	O1^iii—Cd1—O4^v	73.85 (11)
O3—Te1—O4	159.60 (12)	O2^iv—Cd1—O4^v	138.57 (10)
O4^i—Te2—O5	100.25 (14)	O2^v—Cd1—O4^v	66.40 (10)
O4^i—Te2—O3	91.11 (13)	O1—Cd1—O4^v	78.65 (10)
O5—Te2—O3	86.24 (13)	O3—Cd1—O4^v	94.31 (10)
O4^i—Te2—O5^ii	88.71 (13)	Te1—O1—Cd1^vi	119.15 (14)
O5—Te2—O5^ii	76.52 (13)	Te1—O1—Cd1	109.06 (13)
O3—Te2—O5^ii	162.43 (12)	Cd1^vi—O1—Cd1	117.64 (13)
O4^i—Te2—Te2^ii	95.12 (10)	Te1—O2—Cd1^iv	133.44 (16)
O5—Te2—Te2^ii	41.63 (9)	Te1—O2—Cd1^vii	119.05 (14)
O3—Te2—Te2^ii	127.79 (9)	Cd1^iv—O2—Cd1^vii	105.95 (12)
O5^ii—Te2—Te2^ii	34.89 (8)	Te1—O3—Te2	122.67 (15)
O1^iii—Cd1—O2^iv	98.69 (12)	Te1—O3—Cd1	99.09 (12)
O1^iii—Cd1—O2^v	95.20 (12)	Te2—O3—Cd1	138.18 (14)
O2^iv—Cd1—O2^v	74.05 (13)	Te2^viii—O4—Te1	128.18 (16)
O1^iii—Cd1—O1	105.89 (7)	Te2^viii—O4—Cd1^vii	118.13 (14)
O2^iv—Cd1—O1	140.67 (11)	Te1—O4—Cd1^vii	94.15 (10)
O2^v—Cd1—O1	131.97 (12)	Te2—O5—Te2^ii	103.48 (13)

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