Materials Data on KNbO2F by Materials Project
KNbO2F is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. K1+ is bonded to eight equivalent O2- and four equivalent F1- atoms to form KO8F4 cuboctahedra that share corners with twelve equivalent KO8F4 cuboctahedra, faces with six equivalent KO8F4 cuboctahedra, and faces with eight equivalent NbO4F2 octahedra. All K–O bond lengths are 2.97 Å. All K–F bond lengths are 2.86 Å. Nb4+ is bonded to four equivalent O2- and two equivalent F1- atoms to form NbO4F2 octahedra that share corners with six equivalent NbO4F2 octahedra and faces with eight equivalent KO8F4 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Nb–O bond lengths are 2.02 Å. Both Nb–F bond lengths are 2.17 Å. O2- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Nb4+ atoms. F1- is bonded to four equivalent K1+ and two equivalent Nb4+ atoms to form a mixture of distorted edge and corner-sharing FK4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°.