Materials Data on K2MgV2O7 by Materials Project
K2MgV2O7 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.70–3.19 Å. In the second K1+ site, K1+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.91 Å) and four longer (2.97 Å) K–O bond lengths. Mg2+ is bonded to four equivalent O2- atoms to form MgO4 tetrahedra that share corners with four equivalent VO4 tetrahedra. All Mg–O bond lengths are 1.99 Å. V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share a cornercorner with one VO4 tetrahedra and corners with two equivalent MgO4 tetrahedra. There are a spread of V–O bond distances ranging from 1.68–1.84 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+ and two equivalent V5+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three K1+ and one V5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one Mg2+, and one V5+ atom.