Materials Data on Rb2U(SiO3)4 by Materials Project

Abstract

Rb2U(SiO3)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Rb–O bond distances ranging from 2.96–3.64 Å. In the second Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Rb–O bond distances ranging from 2.98–3.36 Å. U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with four SiO4 tetrahedra. There are a spread of U–O bond distances ranging from 1.85–2.30 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one UO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. There is one shorter (1.60 Å) and three longer (1.65 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.64 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent UO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–40°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one UO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three Rb1+ and one U6+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Rb1+, one U6+, and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Rb1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+, one U6+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two Rb1+ and one U6+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Rb1+, one U6+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Rb1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Rb1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Rb1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Rb1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+, one U6+, and one Si4+ atom.