Crystals of calcium potassium cyclo-triphosphate, CaKP3O9, have been synthesized from a melt and structurally characterized using single-crystal X-ray diffraction. The compound is isostructural with the mineral benitoite (BaTiSi3O9).
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (P-O) = 0.001 Å
- R factor = 0.024
- wR factor = 0.056
- Data-to-parameter ratio = 22.8
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ?
Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
correct. If it is not, please give the correct count in the
_publ_section_exptl_refinement section of the submitted CIF.
From the CIF: _diffrn_reflns_theta_max 34.94
From the CIF: _reflns_number_total 639
Count of symmetry unique reflns 357
Completeness (_total/calc) 178.99%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 282
Fraction of Friedel pairs measured 0.790
Are heavy atom types Z>Si present yes
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
1 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
1 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
0 ALERT type 3 Indicator that the structure quality may be low
1 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: Collect (Nonius B.V., 1999); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 2000); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997) and local procedures.
Calcium potassium
cyclo-triphosphate
top
Crystal data top
CaK(P3O9) | Dx = 2.520 Mg m−3 |
Mr = 316.10 | Mo Kα radiation, λ = 0.71073 Å |
Hexagonal, P6c2 | Cell parameters from 455 reflections |
Hall symbol: P -6c 2 | θ = 2.9–33.1° |
a = 6.8090 (3) Å | µ = 1.85 mm−1 |
c = 10.3760 (9) Å | T = 293 K |
V = 416.61 (4) Å3 | Fragment, colourless |
Z = 2 | 0.19 × 0.12 × 0.05 mm |
F(000) = 312 | |
Data collection top
Nonius KappaCCD diffractometer | 639 independent reflections |
Radiation source: fine-focus sealed tube, KappaCCD | 628 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.077 |
φ and ω scans | θmax = 34.9°, θmin = 3.5° |
Absorption correction: multi-scan (SORTAV; Blessing, 1995) | h = −10→10 |
Tmin = 0.794, Tmax = 0.914 | k = −10→10 |
25323 measured reflections | l = −16→16 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.019P)2 + 0.3146P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.024 | (Δ/σ)max < 0.001 |
wR(F2) = 0.056 | Δρmax = 0.44 e Å−3 |
S = 1.18 | Δρmin = −0.40 e Å−3 |
639 reflections | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
28 parameters | Extinction coefficient: 0.130 (6) |
0 restraints | Absolute structure: Flack (1983), 282 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: −0.02 (7) |
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 | x | y | z | Uiso*/Ueq | |
Ca | 0.33333 | 0.66667 | 1.0000 | 0.01396 (15) | |
K | 0.66667 | 0.33333 | 1.0000 | 0.0233 (2) | |
P | 0.73221 (9) | 0.96188 (9) | 0.7500 | 0.01192 (13) | |
O1 | 0.8054 (3) | 0.7734 (3) | 0.7500 | 0.0220 (3) | |
O2 | 0.6141 (2) | 0.9486 (2) | 0.87205 (11) | 0.0239 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ca | 0.0153 (2) | 0.0153 (2) | 0.0113 (3) | 0.00765 (10) | 0.000 | 0.000 |
K | 0.0220 (3) | 0.0220 (3) | 0.0260 (4) | 0.01100 (13) | 0.000 | 0.000 |
P | 0.0098 (2) | 0.0124 (3) | 0.0140 (2) | 0.00589 (19) | 0.000 | 0.000 |
O1 | 0.0127 (7) | 0.0127 (7) | 0.0410 (10) | 0.0067 (7) | 0.000 | 0.000 |
O2 | 0.0284 (7) | 0.0230 (6) | 0.0208 (6) | 0.0131 (5) | 0.0106 (5) | 0.0034 (5) |
Geometric parameters (Å, º) top
Ca—O2i | 2.3309 (12) | K—O2vii | 2.7955 (14) |
Ca—O2ii | 2.3309 (12) | K—O2viii | 2.7955 (14) |
Ca—O2iii | 2.3309 (13) | K—O2ix | 2.7956 (14) |
Ca—O2iv | 2.3309 (12) | P—O1 | 1.592 (2) |
Ca—O2 | 2.3309 (13) | P—O1x | 1.5950 (18) |
Ca—O2v | 2.3309 (13) | P—O2 | 1.4785 (12) |
K—O2iv | 2.7955 (14) | P—O2xi | 1.4785 (12) |
K—O2v | 2.7955 (14) | O1—Pviii | 1.5951 (18) |
K—O2vi | 2.7955 (14) | | |
| | | |
O2i—Ca—O2ii | 89.47 (8) | O2—P—O1x | 107.89 (7) |
O2i—Ca—O2iii | 88.99 (7) | O2xi—P—O1x | 107.89 (7) |
O2ii—Ca—O2iii | 90.77 (5) | O2—P—O2xi | 117.87 (13) |
O2i—Ca—O2iv | 90.77 (5) | P—O1—Pviii | 136.40 (13) |
O2ii—Ca—O2iv | 179.66 (8) | O2iii—Ca—O2 | 179.66 (8) |
O2iii—Ca—O2iv | 89.47 (8) | O2iv—Ca—O2 | 90.77 (5) |
O2i—Ca—O2 | 90.77 (5) | O2i—Ca—O2v | 179.66 (8) |
O2ii—Ca—O2 | 88.99 (7) | O2ii—Ca—O2v | 90.77 (5) |
O2iii—Ca—O2 | 179.66 (8) | O2iii—Ca—O2v | 90.77 (5) |
O2iv—Ca—O2 | 90.77 (5) | O2iv—Ca—O2v | 88.99 (7) |
O2i—Ca—O2v | 179.66 (8) | O2—Ca—O2v | 89.47 (8) |
O2ii—Ca—O2v | 90.77 (5) | O2iv—K—O2v | 71.52 (5) |
O2iii—Ca—O2v | 90.77 (5) | O2iv—K—O2vi | 91.04 (7) |
O2iv—Ca—O2v | 88.99 (7) | O2v—K—O2vi | 99.31 (3) |
O2—Ca—O2v | 89.47 (8) | O2iv—K—O2vii | 99.31 (3) |
O2iv—K—O2v | 71.52 (5) | O2v—K—O2vii | 167.27 (6) |
O2iv—K—O2vi | 91.04 (7) | O2vi—K—O2vii | 71.52 (5) |
O2v—K—O2vi | 99.31 (3) | O2iv—K—O2viii | 99.31 (3) |
O2iv—K—O2vii | 99.31 (3) | O2v—K—O2viii | 91.04 (7) |
O2v—K—O2vii | 167.27 (6) | O2vi—K—O2viii | 167.27 (6) |
O2vi—K—O2vii | 71.52 (5) | O2vii—K—O2viii | 99.31 (3) |
O2iv—K—O2viii | 99.31 (3) | O2iv—K—O2ix | 167.27 (6) |
O2v—K—O2viii | 91.04 (7) | O2v—K—O2ix | 99.31 (3) |
O2vi—K—O2viii | 167.27 (6) | O2vi—K—O2ix | 99.31 (3) |
O2vii—K—O2viii | 99.31 (3) | O2vii—K—O2ix | 91.04 (6) |
O2iv—K—O2ix | 167.27 (6) | O2viii—K—O2ix | 71.52 (5) |
O2v—K—O2ix | 99.31 (3) | O1—P—O1x | 103.60 (13) |
O2vi—K—O2ix | 99.31 (3) | O2—P—O1 | 109.31 (7) |
O2vii—K—O2ix | 91.04 (6) | O2xi—P—O1 | 109.31 (7) |
O2viii—K—O2ix | 71.52 (5) | O2—P—O1x | 107.89 (7) |
O1—P—O1x | 103.60 (13) | O2xi—P—O1x | 107.89 (7) |
O2—P—O1 | 109.31 (7) | O2—P—O2xi | 117.87 (13) |
O2xi—P—O1 | 109.31 (7) | P—O1—Pviii | 136.40 (13) |
Symmetry codes: (i) −y+1, x−y+1, z; (ii) −x+y, y, −z+2; (iii) −y+1, −x+1, −z+2; (iv) −x+y, −x+1, z; (v) x, x−y+1, −z+2; (vi) −x+y, y−1, −z+2; (vii) x, y−1, z; (viii) −y+2, x−y+1, z; (ix) −y+2, −x+1, −z+2; (x) −x+y+1, −x+2, z; (xi) x, y, −z+3/2. |