A new paper on a novel KCl-hydrate discovered under pressure

Dr. Keishiro Yamashita, who received his Ph.D. in March 2022, has published a paper from Acta Crystallographica C on a new high-pressure phase of KCl hydrate. A figure from this paper was selected for the cover of Acta Cryst. C.

During the crystal growth of the new KCl hydrate, high-pressure phases of water (ice) unavoidably crystallise simultaneously. Dr Yamashita optimised the crystallisation conditions to suppress formation of low-symmetry high-pressure phases of ice (ice VI) and obtained diffraction patterns of the new hydrate with high-symmetry ice VII. Thanks to this, crystal-structure determination was enabled.

X-ray diffraction is not capable of detecting hydrogen atoms in crystal structures, but by combining DFT calculations, Dr Yamashita successfully discussed the hydrogen-chloride bondings in the crystal structure.

• Yamashita K., Komatsu K., and Kagi H. (2022) Crystal structure of potassium chloride monohydrate: water intercalation into the B1 structure of KCl under high pressure. Acta Crystallographica Section C, 78, 749-754. https://doi.org/10.1107/S2053229622011135