Krypton oxides under pressure

TL;DR

This paper predicts that under high pressure, krypton can form stable compounds with oxygen, including a stable KrO monoxide, using advanced computational methods.

Contribution

It introduces the prediction of stable krypton oxides under high pressure, a novel insight into noble gas chemistry.

Findings

KrO is predicted to form spontaneously at around 300 GPa.

KrO is thermodynamically and dynamically stable at high pressure.

KrO forms non-molecular crystals with genuine chemical bonds.

Abstract

Under high pressure, krypton, one of the most inert elements is predicted to become sufficiently reactive to form a new class of krypton compounds; krypton oxides. Using modern ab-initio evolutionary algorithms in combination with Density Functional Theory, we predict the existence of several thermodynamically stable Kr/O species at elevated pressures. In particular, our calculations indicate that at approx. 300 GPa the monoxide, KrO, should form spontaneously and remain thermo- and dynamically stable with respect to constituent elements and higher oxides. The monoxide is predicted to form non-molecular crystals with short Kr-O contacts, typical for genuine chemical bonds.