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Indexed by:Journal Papers

Date of Publication:2019-06-01

Journal:PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL

Included Journals:SCIE

Volume:29

Issue:3,SI

Page Number:329-334

ISSN No.:1002-0071

Key Words:1,1-Diamino-2; 2-Dinitroethene; Anisotropic behavior; Raman spectra; Phase transformation

Abstract:Using dispersion-corrected density functional theory (DFT), we investigate the effect of uniaxial compression on 1, 1-diamino-2, 2-dinitroethene (FOX-7) crystal. Principal and shear stresses along the [100], [010], and [001] orientations exhibit considerable anisotropic compressibility. Raman spectra are complemented by DFT calculations in vibrational modes. Several abnormal pressure-induced changes in selected Raman modes are observed along the [100] orientation. Combined Raman peak shifts with inter/intra-molecular hydrogen bonds and N-H/N-O covalent bonds, the results demonstrate that the spectroscopic variation are associated with the rearrangement of hydrogen-bonded networks of FOX-7 crystal. These findings imply a possible phase transformation or some minor changes in molecular conformation in the pressure regions under uniaxial compression.