Materials Data on KEr(SeO4)2 by Materials Project
KEr(SeO4)2 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.68–3.35 Å. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.60–3.37 Å. There are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Er–O bond distances ranging from 2.28–2.58 Å. In the second Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Er–O bond distances ranging from 2.23–2.71 Å. There are four inequivalent Se6+ sites. In the first Se6+ site, Se6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Se–O bond distances ranging from 1.66–1.69 Å. In the second Se6+ site, Se6+ is bonded in a tetrahedral geometry to four O2- atoms. There is three shorter (1.67 Å) and one longer (1.68 Å) Se–O bond length. In the third Se6+ site, Se6+ is bonded in a tetrahedral geometry to four O2- atoms. All Se–O bond lengths are 1.67 Å. In the fourth Se6+ site, Se6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Se–O bond distances ranging from 1.66–1.69 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+, one Er3+, and one Se6+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Er3+ and one Se6+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Er3+ and one Se6+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Er3+ and one Se6+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Er3+, and one Se6+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Er3+ and one Se6+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Er3+, and one Se6+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Er3+ and one Se6+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+, one Er3+, and one Se6+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Er3+, and one Se6+ atom. In the eleventh O2- site, O2- is bonded in a distorted tetrahedral geometry to two K1+, one Er3+, and one Se6+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one Er3+, and one Se6+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Er3+, and one Se6+ atom. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two K1+, one Er3+, and one Se6+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Er3+, and one Se6+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Er3+, and one Se6+ atom.