Materials Data on UN2O7 by Materials Project
UN2O7 crystallizes in the orthorhombic Pbcn space group. The structure is two-dimensional and consists of two UN2O7 sheets oriented in the (0, 1, 0) direction. U6+ is bonded in a distorted octahedral geometry to six O2- atoms. There are a spread of U–O bond distances ranging from 1.79–2.45 Å. N4+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.29 Å) N–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.90 Å) and two longer (3.17 Å) O–O bond lengths. In the second O2- site, O2- is bonded in a single-bond geometry to one U6+ and one O2- atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one U6+ and one N4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one U6+, one N4+, and one O2- atom.