DOE OSTI2020
Nd7Se4O17Cl3 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are seven inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Nd–O bond distances ranging from 2.36–2.82 Å. In the second Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.32–2.85 Å. In the third Nd3+ site, Nd3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.36–2.65 Å. In the fourth Nd3+ site, Nd3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.33–2.67 Å. In the fifth Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to six O2- and two Cl1- atoms. There are a spread of Nd–O bond distances ranging from 2.33–2.68 Å. There are one shorter (3.12 Å) and one longer (3.18 Å) Nd–Cl bond lengths. In the sixth Nd3+ site, Nd3+ is bonded in a 6-coordinate geometry to six O2- and two Cl1- atoms. There are a spread of Nd–O bond distances ranging from 2.33–2.52 Å. There are one shorter (3.06 Å) and one longer (3.10 Å) Nd–Cl bond lengths. In the seventh Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to five O2- and three Cl1- atoms. There are a spread of Nd–O bond distances ranging from 2.34–2.46 Å. There are a spread of Nd–Cl bond distances ranging from 2.92–3.20 Å. There are four inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.71–1.77 Å. In the second Se4+ site, Se4+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.72–1.77 Å. In the third Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.70–1.76 Å. In the fourth Se4+ site, Se4+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.70–1.78 Å. There are seventeen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of edge and corner-sharing ONd4 tetrahedra. In the second O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of edge and corner-sharing ONd4 tetrahedra. In the third O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of edge and corner-sharing ONd4 tetrahedra. In the fourth O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of edge and corner-sharing ONd4 tetrahedra. In the fifth O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of edge and corner-sharing ONd4 tetrahedra. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Nd3+ and one Se4+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Nd3+ and one Se4+ atom. In the eighth O2- site, O2- is bonded to three Nd3+ and one Se4+ atom to form a mixture of distorted edge and corner-sharing ONd3Se tetrahedra. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Nd3+ and one Se4+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two Nd3+ and one Se4+ atom. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to three Nd3+ and one Se4+ atom. In the twelfth O2- site, O2- is bonded in a distorted water-like geometry to one Nd3+ and one Se4+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Nd3+ and one Se4+ atom. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to three Nd3+ and one Se4+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Nd3+ and one Se4+ atom. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Nd3+ and one Se4+ atom. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to three Nd3+ and one Se4+ atom. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two Nd3+ atoms. In the second Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two Nd3+ atoms. In the third Cl1- site, Cl1- is bonded in a 3-coordinate geometry to three Nd3+ atoms.