Molecular characteristics of H2O in hydrate/ice/liquid water mixture

Abstract

The interfacial properties of hydrate and its ambient play an important role in hydrate technique. In this paper, the molecular characteristics of H2O in hydrate/ice/liquid water mixture system are investigated based on molecular dynamics (MD) simulations. The structure I (sI) methane hydrate is partially heated to obtain the studied system. The properties including hydrogen bond, radial distribution function (RDF) and F3 order parameter (tetrahedral coordinated parameter of H2O) indicate that there is little difference of water structure in the hydrate region and ice/liquid water mixture region. The F4 order parameter (parameter based on H–O–O–H torsion angles of H2O) could be used to distinguish the different region. The value of F4 experiences the continuous change at interface between mixture region and hydrate region.