Equation of state of KI up to 150 GPa

The equation of state of potassium iodide, KI, has been determined up to 156 GPa at 298 K by angular-dispersive X-ray diffraction in diamond-anvil-cell. Helium pressure transmitting medium was used to minimize non-hydrostatic stress on the sample. The B2 phase is stable at least between 2 and 156 GPa. Pressure-volume data were fitted using a Rydberg-Vinet equation of state. The volume, isothermal bulk modulus and its pressure derivative of B2-KI at ambient pressure are V-0=79.2 +/- 2.5 angstrom(3), K-0=11.9 +/- 1.2 GPa and K-0'=6.01 +/- 0.11. It allows using KI as a pressure calibrant in high pressure experiments.