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Updated: Jul 11, 2026

High Pressure Single Crystal Diffraction at PX^2
Published on: January 16, 2017
X-ray Diffraction to 302 Gigapascals: High-Pressure Crystal Structure of Cesium Iodide
Abstract:
X-ray diffraction measurements have been carried out on cesium iodide (CsI) to 302 gigapascals with a platinum pressure standard. The results indicate that above 200 gigapascals CsI at 300 K has a hexagonal close-packed crystal structure with the ideal c/a ratio of 1.63 +/- 0.01. The crystal structure and pressure-volume relations converge at high pressure with those of solid xenon, which is isoelectronic with CsI. The results indicate a significant loss of ionic bonding in the hexagonal close-packed metallic phase of CsI at ultrahigh pressure.
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