Materials Data on Rb7NaSi8 by Materials Project
RbRb6NaSi8 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional and consists of four rubidium molecules and one Rb6NaSi8 framework. In the Rb6NaSi8 framework, Rb1+ is bonded in a 6-coordinate geometry to six Si1- atoms. There are a spread of Rb–Si bond distances ranging from 3.54–3.82 Å. Na1+ is bonded in a 6-coordinate geometry to six equivalent Si1- atoms. All Na–Si bond lengths are 2.96 Å. There are two inequivalent Si1- sites. In the first Si1- site, Si1- is bonded in a 9-coordinate geometry to six equivalent Rb1+ and three equivalent Si1- atoms. All Si–Si bond lengths are 2.42 Å. In the second Si1- site, Si1- is bonded in a 1-coordinate geometry to four equivalent Rb1+, one Na1+, and three Si1- atoms. Both Si–Si bond lengths are 2.48 Å.