Materials Data on Nd2Cu(GeO4)2 by Materials Project
CuNd2Ge2O8 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Nd3+ sites. In the first 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 2.36–2.83 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 2.35–2.93 Å. Cu2+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.90–2.74 Å. There are three inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.79 Å) and two longer (1.80 Å) Ge–O bond length. In the second Ge4+ site, Ge4+ is bonded to five O2- atoms to form corner-sharing GeO5 trigonal bipyramids. There are a spread of Ge–O bond distances ranging from 1.78–1.99 Å. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form corner-sharing GeO4 tetrahedra. There is two shorter (1.77 Å) and two longer (1.81 Å) Ge–O bond length. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to two Nd3+, one Cu2+, and one Ge4+ atom to form a mixture of distorted edge and corner-sharing ONd2CuGe trigonal pyramids. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nd3+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nd3+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nd3+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded to two Nd3+, one Cu2+, and one Ge4+ atom to form a mixture of distorted edge and corner-sharing ONd2CuGe trigonal pyramids. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Nd3+ and two Ge4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Nd3+, one Cu2+, and one Ge4+ atom. In the eighth O2- site, O2- is bonded to two Nd3+, one Cu2+, and one Ge4+ atom to form a mixture of distorted edge and corner-sharing ONd2CuGe trigonal pyramids. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nd3+ and one Ge4+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Nd3+, two equivalent Cu2+, and one Ge4+ atom.