The compression mechanism of CrF3
The structure of CrF3 has been studied in the pressure range from ambient to 9.12 GPa by time-of-flight neutron powder diffraction. Rietveld refinements of the crystal structure were performed in the space group for all the recorded data sets. It was found that volume reduction is achieved through rotation of the CrF6 octahedra and that the Cr—F—Cr bond angle decreases from 144.80 (7) to 133.9 (4)° within the investigated pressure range. Furthermore, a small octahedral strain was found to develop during compression. The octahedral strain reflects an elongation of the CrF6 octahedra along the c-axis direction. The zero-pressure bulk modulus Bo and its pressure derivative B were determined to be Bo = 29.2 (4) GPa and = 10.1 (3).