Materials Data on Sr2U2O7 by Materials Project
Sr2U2O7 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.50–2.81 Å. In the second Sr2+ site, Sr2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.59–2.94 Å. There are two inequivalent U5+ sites. In the first U5+ site, U5+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of U–O bond distances ranging from 2.01–2.63 Å. In the second U5+ site, U5+ is bonded to six O2- atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of U–O bond distances ranging from 2.04–2.23 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to three Sr2+ and one U5+ atom to form a mixture of distorted edge and corner-sharing OSr3U tetrahedra. In the second O2- site, O2- is bonded to three Sr2+ and one U5+ atom to form a mixture of distorted edge and corner-sharing OSr3U tetrahedra. In the third O2- site, O2- is bonded to three Sr2+ and one U5+ atom to form a mixture of distorted edge and corner-sharing OSr3U tetrahedra. In the fourth O2- site, O2- is bonded to three Sr2+ and one U5+ atom to form a mixture of distorted edge and corner-sharing OSr3U tetrahedra. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+ and three U5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and three U5+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Sr2+ and three U5+ atoms.