New Phase Diagram of Water under Negative Pressure: Rise of The Lowest-Density Ice Clathrates

ORAL

Abstract

Using Monte Carlo packing algorithm and dispersion-corrected density functional theory, we predict a crystalline clathrate of cubic structure III (s-III) with mass density of 0.593 g/cm3 composed of two large icosihexahedral cavities (8668412) and six small decahedral cavities (8248) per unit cell [Sci. Adv. 2016, 2, e1501010]. A new phase diagram of water ice with TIP4P/2005 model potential is constructed, where the s-III clathrate emerges as the most stable ice polymorph in the pressure region below −5834 bar at 0 K and below −3411 bar at 300 K. Inspired by this discovery, another cubic crystalline phase of s-IV with even lower density of 0.506 g/cm3 is found a stable phase in the phase diagram. Given that s-III and s-IV can be related to the silica analog of ROH and FAU, respectively, we explore all the possible clathrates from database of zeolite structures and find that a FAU ice clathrate with ultralow density (0.5 g/cm3) in the phase diagram. Finally, the new phase diagram under negative pressure is updated. With pressure decreasing, ice Ih emerges firstly, then s-II ice clathrate dominates. Below s-II, s-IV arises at low temperature and FAU dominates at high temperature.

–

Presenters

  • Jijun Zhao

    School of Physics, Dalian University of Technology, Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian University of Technology, Dalian, China, School of Physics and Optoelectronic Engineering

Authors

  • Jijun Zhao

    School of Physics, Dalian University of Technology, Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian University of Technology, Dalian, China, School of Physics and Optoelectronic Engineering

  • YINGYING HUANG

    School of Physics, Dalian University of Technology, Dalian University of Technology, Dalian, China, School of Physics and Optoelectronic Engineering

  • Chongqin Zhu

    University of Nebraska, University of Nebraska, Lincoln, NE 68588, USA, Department of Chemistry and Nebraska Center for Materials and Nanoscience

  • Yuan Liu

    Beijing University of Chemical Technology

  • Xiao Zeng

    Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, University of Nebraska, University of Nebraska, Lincoln, NE 68588, USA, Department of Chemistry and Nebraska Center for Materials and Nanoscience