Observation of the incommensurate barium-IV structure in strontium phase V

A previously unknown type of elemental structure has been discovered recently in barium, phase IV. The structure is composed of a host'' and two or more guest components made up of chains that lie in channels in the host, and form structures that are incommensurate with the host. This implies a segregation into different electronic species. The same structure has now been found in phase V of Sr above 45 GPa.