Electronic signature of low dimensional ice-like water

Abstract

The structure and phase of water are closely related to the hydrogen bond (HB). When water is confined in low dimensional materials, it can form unusual HB network due to the geometric constraints. Water molecules inside the (8,8) carbon nanotube take stacked-pentagonal ring structure and form a monolayer between 6Å graphene sheets. We here present the nature of HB in low dimensional ice-like water using a first-principle energy decomposition method. In addition to the geometric differences compared to the hexagonal ice with tetrahedral bonding pattern, we observed the weakened HBs in ice-like water inside low dimensional materials. The distortion of lone pair electrons of water from a tetrahedral symmetry due to the confinement effect reduces the strength of HB in ice-like water. The comparative analysis reported in this work can provide the insight into the highly confined system such as biological channels and interfacial water system.