Electronic, dielectric and optical properties of two dimensional and bulk ice: a multi-scale simulation study

TL;DR

This study uses multi-scale simulations to investigate the electronic, dielectric, and optical properties of two-dimensional and bulk ices, revealing anisotropic dielectric behavior and ultraviolet absorption characteristics.

Contribution

It provides the first comprehensive analysis of electronic and optical properties of 2D-ices using DFT, DFPT, and molecular dynamics, filling a knowledge gap in their electronic behavior.

Findings

In-plane electronic dielectric constant is larger than out-of-plane for 2D-ices.

Total out-of-plane dielectric constant exceeds 2 for all 2D-ices.

Absorption energies of 2D-ices are in the ultraviolet spectrum.

Abstract

The intercalated water into nanopores exhibits anomalous properties such as ultralow dielectric constant.~Multi-scale modeling and simulations are used to investigate the dielectric properties of various crystalline two-dimensional ices and bulk ices. Although, the structural properties of two-dimensional (2D-) ices have been extensively studied, much less is known about their electronic and optical properties. First, by using density functional theory (DFT) and density functional perturbation theory (DFPT), we calculate the key electronic, optical and dielectric properties of 2D-ices. Performing DFPT calculations, both the ionic and electronic contributions of the dielectric constant are computed. The in-plane electronic dielectric constant is found to be larger than the out-of-plane dielectric constant for all the studied 2D-ices. The in-plane dielectric constant of the electronic response is found to be isotropic for all the studied ices. Secondly, we determined the dipolar dielectric constant of 2D-ices using molecular dynamics simulations (MDS) at finite temperature. The total out-of-plane dielectric constant is found to be larger than 2 for all the studied 2D-ices. Within the framework of the random-phase approximation (RPA), the absorption energy ranges for 2D-ices are found to be in the ultraviolet spectra. For the comparison purposes, we also elucidate the electronic, dielectric and optical properties of four crystalline ices (ice VIII, ice XI, ice Ic and ice Ih) and bulk water.