Materials Data on K2NaMnF6 by Materials Project
K2NaMnF6 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded to twelve F1- atoms to form KF12 cuboctahedra that share corners with twelve equivalent KF12 cuboctahedra, faces with six equivalent KF12 cuboctahedra, faces with four equivalent NaF6 octahedra, and faces with four equivalent MnF6 octahedra. There are four shorter (2.94 Å) and eight longer (3.02 Å) K–F bond lengths. Na1+ is bonded to six F1- atoms to form NaF6 octahedra that share corners with six equivalent MnF6 octahedra and faces with eight equivalent KF12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.25 Å) and two longer (2.26 Å) Na–F bond lengths. Mn3+ is bonded to six F1- atoms to form MnF6 octahedra that share corners with six equivalent NaF6 octahedra and faces with eight equivalent KF12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.91 Å) and two longer (2.11 Å) Mn–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted linear geometry to four equivalent K1+, one Na1+, and one Mn3+ atom. In the second F1- site, F1- is bonded to four equivalent K1+, one Na1+, and one Mn3+ atom to form a mixture of distorted edge and corner-sharing FK4NaMn octahedra. The corner-sharing octahedra tilt angles range from 0–3°.