DOE OSTI2020
CdP2H6O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with five PHO3 tetrahedra and an edgeedge with one CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.30–2.40 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to one H+0.33+ and three O2- atoms to form distorted PHO3 tetrahedra that share corners with three equivalent CdO6 octahedra. The corner-sharing octahedra tilt angles range from 52–54°. The P–H bond length is 1.41 Å. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the second P5+ site, P5+ is bonded to one H+0.33+ and three O2- atoms to form distorted PHO3 tetrahedra that share corners with two equivalent CdO6 octahedra. The corner-sharing octahedral tilt angles are 44°. The P–H bond length is 1.40 Å. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. There are six inequivalent H+0.33+ sites. In the first H+0.33+ site, H+0.33+ is bonded in a single-bond geometry to one P5+ atom. In the second H+0.33+ site, H+0.33+ is bonded in a single-bond geometry to one P5+ atom. In the third H+0.33+ site, H+0.33+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.61 Å) H–O bond length. In the fourth H+0.33+ site, H+0.33+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H+0.33+ site, H+0.33+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the sixth H+0.33+ site, H+0.33+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.52 Å) H–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Cd2+, one P5+, and one H+0.33+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cd2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cd2+, one P5+, and one H+0.33+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one P5+ and one H+0.33+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one Cd2+ and two H+0.33+ atoms. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one Cd2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to one P5+ and one H+0.33+ atom.