Department of Earth Sciences, University of Cambridge, Cambridge, UK.
J Phys Condens Matter. 2011 Jun 8;23(22):225402. doi: 10.1088/0953-8984/23/22/225402. Epub 2011 May 17.
The temperature dependence of the crystal structures of the low-temperature α-phase and the intermediate-temperature β-phase of crystalline malononitrile, CH(2)(CN)(2), have been determined using Rietveld refinement on neutron powder diffraction data. The results confirm that the α-phase has the same structure as the high-temperature γ-phase, and the refined structure of the β-phase is in agreement with previous structure determination using single-crystal x-ray diffraction. The variations of the structure with temperature due to the phase transitions are identified and analysed in terms of molecular rotations and spontaneous strains.
利用中子粉末衍射数据的 Rietveld 精修，确定了低温α相和中温β相晶态丙二腈（CH(2)(CN)(2)）的晶体结构随温度的变化。结果证实，α相具有与高温γ相相同的结构，β相的精修结构与先前使用单晶 X 射线衍射确定的结构一致。通过分子旋转和自发应变，确定并分析了相变引起的结构随温度的变化。
