Acta Cryst. (2008). E64, i24-i25  [ doi:10.1107/S1600536808010441 ]

Redetermination of the borax structure from laboratory X-ray data at 145 K

G. J. Gainsford, T. Kemmitt and C. Higham

Abstract: The title compound, sodium tetraborate decahydrate (mineral name: borax), Na₂[B₄O₅(OH)₄]·8H₂O, has been studied previously using X-ray [Morimoto (1956). Miner. J. 2, 1-18] and neutron [Levy & Lisensky (1978). Acta Cryst. B34, 3502-3510] diffraction data. The structure contains tetraborate anions [B₄O₅(OH)₄]^2- with twofold rotation symmetry, which form hydrogen-bonded chains, and [Na(H₂O)₆] octahedra that form zigzag chains [Na(H₂O)_4/2(H₂O)_2/1]. The O-H bond distances obtained from the present redetermination at 145 K are shorter than those in the neutron study by an average of 0.127 (19) Å.

Online 23 April 2008

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