J G Thompson et al 1988 J. Phys. C: Solid State Phys. 21 4007 doi:10.1088/0022-3719/21/22/016
J G Thompson, A D Rae, R L Withers, T R Welberry and A C Willis
Show affiliationsThe crystal structure has been redetermined using X-ray diffraction data collected from a triply twinned crystal, a=10.8568(8), b=6.2682(5), c=5.0340(7)AA, Cmc21 grown using I2 as the vapour transport agent. The weak orthorhombic superlattice originally observed by convergent-beam electron diffraction, corresponding to the freezing in of a q=1/3(1120) Sigma 6 sub-cell phonon mode, is confirmed, and magnitudes of the atomic displacements from their ideal positions refined. Closer inspection of the data revealed the presence of a q=0, Sigma 6u symmetry, frozen-in-phonon mode, which depending on its sign when added to the q=1/3(1120) mode, results in two homometric solutions.
Issue 22 (10 August 1988)
J G Thompson et al 1988 J. Phys. C: Solid State Phys. 21 4007