The structure of K2TeO3 - an experimental and theoretical study

The single-crystal structure of K2TeO3 is presented with Mr=253.8, trigonal, Panti 3, a=6.279(2), c=7.069(4) A, V=241.4(2) A3, Z=2, Dx=3.492(3) Mg m-3, Mo Kα, λ=0.71069 A, μ=7.77 mm-1, F(000)=228, T=293 K, 572 observed reflections gave R=0.049. The structure consists of free TeO32- ions with the Te atom on the threefold axis. The Te-O bond distance, corrected for thermal motion using the riding model, is 1.836(6) A and the angle O-Te-O is 101.5(2)0. The next-closest Te-O distance is 3.902(5) A. Restricted Hartree-Fock self-consistent field (RHF-SCF) calculations using a frozen-orbital effective-core-potential description for Te are presented for the TeO32- ion with and without the inclusion of the cyrstal field. The optimized Te-O bond distance in K2TeO3 was 0.03 A longer than in experiment. (orig.)