DOE OSTI2020
Na2CdO3 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with four equivalent CdO6 octahedra, edges with four equivalent CdO6 octahedra, and edges with eight NaO6 octahedra. The corner-sharing octahedra tilt angles range from 7–8°. There are two shorter (2.34 Å) and four longer (2.50 Å) Na–O bond lengths. In the second Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with four equivalent CdO6 octahedra, edges with four equivalent CdO6 octahedra, and edges with eight NaO6 octahedra. The corner-sharing octahedra tilt angles range from 6–8°. There are a spread of Na–O bond distances ranging from 2.37–2.52 Å. In the third Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with six NaO6 octahedra, edges with six NaO6 octahedra, and edges with six equivalent CdO6 octahedra. The corner-sharing octahedral tilt angles are 8°. All Na–O bond lengths are 2.42 Å. Cd is bonded to six O atoms to form CdO6 octahedra that share corners with six NaO6 octahedra, edges with three equivalent CdO6 octahedra, and edges with nine NaO6 octahedra. The corner-sharing octahedra tilt angles range from 6–8°. There are four shorter (2.25 Å) and two longer (2.26 Å) Cd–O bond lengths. There are two inequivalent O sites. In the first O site, O is bonded to four Na and two equivalent Cd atoms to form a mixture of edge and corner-sharing ONa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. In the second O site, O is bonded to four Na and two equivalent Cd atoms to form a mixture of edge and corner-sharing ONa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 0–6°.