title: 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.
authors.forename: H K
authors.initials: HK
authors.lastname: Mao
authors.forename: R J
authors.initials: RJ
authors.lastname: Hemley
authors.forename: L C
authors.initials: LC
authors.lastname: Chen
authors.forename: J F
authors.initials: JF
authors.lastname: Shu
authors.forename: L W
authors.initials: LW
authors.lastname: Finger
authors.forename: Y
authors.initials: Y
authors.lastname: Wu