X-ray crystallography of simple molecular solids up to megabar pressures: Application to solid oxygen and carbon dioxide

Abstract

A review of recently developed methods to study the structural properties of simple molecular solids under pressures up to the megabar range using synchrotron X-ray diffraction techniques is presented. This includes the growth of single-crystals at high pressure and temperature conditions and the use of He as pressuretransmitting medium. The application of these methods to solid O2 and CO2 is then presented as illustrative examples, showing how they enabled to solve long-standing debates on the structure of the high-pressure crystalline phases of these compounds.