Ab initio investigation of optical properties of high-pressure phases of ice

TL;DR

This study uses ab initio methods to analyze how high pressure alters the optical properties of different ice phases, revealing significant shifts and enhancements in optical responses with increasing pressure.

Contribution

It provides a comprehensive ab initio analysis of optical properties of multiple ice phases under high pressure, including new insights into pressure-induced changes.

Findings

Optical properties of ice shift towards blue with pressure.

Absorption and reflection peaks increase under high pressure.

Transmissivity decreases as absorption and reflection increase.

Abstract

We report a detailed ab initio investigation on the optical properties of ice under a wide high pressure range. The ice X phase (up to 380GPa), the theoretical proposed higher pressure phase ice XV (300GPa), as well as the ambient pressure low-temperature phase ice XI are involved. Our results show that the dispersion relations of optical properties of ice under high pressure are quite different from those under ambient pressure. Under higher pressure, there is whole tendency of blue shift in all optical properties of ice, and the energy region for optical response become broader, such as the absorption band and reflection band. In addition to the augmented absorption edge, all absorption peaks are found to be rising, and the reflection peaks are also enhanced a bit; hence the transmissivity of ice is inferred to be dropping. The photoconductivity is enhanced, and we explain this behavior from the increase of earner density. The static optical properties are found to be pressure independent, and principally due to the network topology of hydrogen bonding.