Structures of metastable water ice XVII with different guests molecules

Very recently, we have studied the crystalline structure of the C0-phase H2-filled ice (recovered at room pressure and low temperature) and ice XVII, a new form of ice discovered by our group. This new ice (obtained by heating C0-phase H2-filled ice at about 110 K under dynamic vacuum) is so porous that it can reabsorb H2 and other gases, and release them repetitively. After our first diffraction measurements, several issues remain still unresolved. This proposal aims to study the structure of ice XVII, both empty and with a variable quantity of refilled molecules (D2, Ne, Ar), so solve the open issues about the effect of the guest on the structure, and the possible formation of a proton-ordered form of the empty structure. Data will be analyzed through Rietveld refinement, in order to accurately determine the positions of the atoms in the unit cell.