Download citation
Download citation
link to html
The atomic interactions and anharmonicity of atomic displacements in the virtual ferroelectric KTaO3, potassium tantalate, have been studied using accurate single-crystal X-ray diffraction at room temperature. The multipole analysis of electron density and Gram-Charlier series description of anharmonic atomic displacements allowed us to perform a quantitative analysis of the chemical bonding and atomic motion in this crystal. Closed-shell interactions between Ta-O and K-O pairs of atoms were found, while no interaction was observed for the Ta-K and O-O atomic pairs. The character of the anharmonic atomic displacements is discussed and compared with those in SrTiO3.

Supporting information


Crystallographic Information File (CIF)
Contains datablocks global, KTaO3


Structure factor file (CIF format)
Contains datablock KTaO3

Computing details top

Data reduction: Zucker et al. (1983); program(s) used to solve structure: Zucker et al. (1983); program(s) used to refine structure: Protas, J.(1997).

(KTaO3) top
Crystal data top
KO3TaMo Kα radiation, λ = 0.71069 Å
Mr = 268.05Cell parameters from 25 reflections
Cubic, Pm3mθ = 30–45°
Hall symbol: -P 4 2 3µ = 44.68 mm1
a = 3.9883 (2) ÅT = 298 K
V = 63.44 Å3Sphere, colorless
Z = 10.11 × 0.11 × 0.11 × 0.06 (1) (radius) mm
Dx = 7.016 Mg m3
Data collection top
Enraf Nonius CAD-4
Rint = 0.020
ω/2θ scansθmax = 64.5°
Absorption correction: for a sphere
Zucker et al. (1983)
h = 1010
k = 07
2183 measured reflectionsl = 05
148 independent reflections3 standard reflections every 100 reflections
148 reflections with F > 3σ(F) intensity decay: none
Refinement top
Refinement on F w = 1/(s**2 + 0.00002F**2)
R[F2 > 2σ(F2)] = 0.004(Δ/σ)max < 0.001
wR(F2) = 0.005Δρmax = 0.1 e Å3
S = 1.05Δρmin = 0.1 e Å3
148 reflectionsExtinction correction: Becker-Coppens type 2
28 parametersExtinction coefficient: 0.02085
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
K0. (2)*
O0. (8)
Ta0. (3)*
Atomic displacement parameters (Å2) top
O0.0035 (8)0.0092 (4)0.0092 (4)
Geometric parameters (Å, º) top

Follow Acta Cryst. B
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds