DOI: 10.17188/1672168
title: Materials Data on KMg14BO16 by Materials Project

description: KMg14BO16 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. K1+ is bonded to six O2- atoms to form KO6 octahedra that share corners with two equivalent KO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.21 Å) and four longer (2.37 Å) K–O bond lengths. There are six inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with two equivalent KO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent BO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.88–2.52 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent KO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Mg–O bond distances ranging from 2.12–2.22 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent KO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Mg–O bond distances ranging from 2.12–2.22 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent BO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are a spread of Mg–O bond distances ranging from 2.05–2.23 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent KO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Mg–O bond distances ranging from 2.12–2.22 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, an edgeedge with one KO6 octahedra, an edgeedge with one BO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–20°. There are a spread of Mg–O bond distances ranging from 2.14–2.21 Å. B3+ is bonded to six O2- atoms to form BO6 octahedra that share corners with two equivalent BO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There is four shorter (1.73 Å) and two longer (2.21 Å) B–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to one K1+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OKMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. In the second O2- site, O2- is bonded in a 6-coordinate geometry to five Mg2+ and one B3+ atom. Both O–Mg bond lengths are 2.23 Å. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Mg2+ and one B3+ atom. There are two shorter (2.14 Å) and two longer (2.23 Å) O–Mg bond lengths. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with eight OKMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. In the fifth O2- site, O2- is bonded to two equivalent K1+ and four Mg2+ atoms to form OK2Mg4 octahedra that share corners with six OK2Mg4 octahedra and edges with twelve OKMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OK2Mg4 octahedra and edges with eight OKMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh O2- site, O2- is bonded to four equivalent Mg2+ and two equivalent B3+ atoms to form a mixture of edge and corner-sharing OMg4B2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to one K1+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OKMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. Both O–Mg bond lengths are 2.16 Å. In the ninth O2- site, O2- is bonded in a 6-coordinate geometry to five Mg2+ and one B3+ atom. The O–Mg bond length is 2.52 Å.