Materials Data on Nd2HgO4 by Materials Project
Nd2HgO4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded to seven O2- atoms to form distorted edge-sharing NdO7 pentagonal bipyramids. There are a spread of Nd–O bond distances ranging from 2.34–2.58 Å. In the second 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 2.33–2.59 Å. Hg2+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are two shorter (2.02 Å) and two longer (2.96 Å) Hg–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Nd3+ and one Hg2+ atom to form a mixture of distorted edge and corner-sharing ONd3Hg tetrahedra. In the second O2- site, O2- is bonded to three Nd3+ and one Hg2+ atom to form a mixture of distorted edge and corner-sharing ONd3Hg 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 in a 6-coordinate geometry to four Nd3+ and two equivalent Hg2+ atoms.