In:
Acta Crystallographica Section B Structural Science, International Union of Crystallography (IUCr), Vol. 57, No. 3 ( 2001-06-01), p. 296-302
Abstract:
The structures of the high- and low-temperature phases of 38% brominated BCCD [betaine (trimethylammonioacetate) calcium chloride dihydrate], the latter being known as the X-phase, have been determined by single-crystal neutron diffraction at 295 and 20 K, respectively. The symmetry of the X-phase is described by the P 2 1 2 1 2 1 space group. The distortion with respect to the high-temperature Pnma phase is characterized by anti-symmetric displacements of the betaine molecules as well as of the Ca octahedra. On the basis of a symmetry-mode analysis, we propose an interpretation of the direct phase transition that occurs around 80 K between these two phases.
Type of Medium:
Online Resource
ISSN:
0108-7681
DOI:
10.1107/S0108768101001525
DOI:
10.1107/S0108768101001525/lc0032sup1.cif
DOI:
10.1107/S0108768101001525/lc0032295Ksup2.hkl
DOI:
10.1107/S0108768101001525/lc003220Ksup3.hkl
Language:
Unknown
Publisher:
International Union of Crystallography (IUCr)
Publication Date:
2001
detail.hit.zdb_id:
2020841-8
SSG:
13