Materials Data on NaPr(Si3O7)2 by Materials Project

Abstract

NaPr(Si3O7)2 crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.39 Å) and four longer (2.81 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.61 Å) and four longer (2.68 Å) Na–O bond lengths. Pr3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Pr–O bond distances ranging from 2.35–2.83 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. 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 (1.63 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.58–1.66 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Pr3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Pr3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Pr3+ and two Si4+ atoms.