Materials Data on K(FeSb3)4 by Materials Project
KFe4Sb12 crystallizes in the cubic Im-3 space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent Sb1- atoms to form KSb12 cuboctahedra that share faces with eight equivalent FeSb6 octahedra. All K–Sb bond lengths are 3.45 Å. Fe+2.75+ is bonded to six equivalent Sb1- atoms to form FeSb6 octahedra that share corners with six equivalent FeSb6 octahedra and faces with two equivalent KSb12 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. All Fe–Sb bond lengths are 2.58 Å. Sb1- is bonded in a 2-coordinate geometry to one K1+, two equivalent Fe+2.75+, and two equivalent Sb1- atoms. There are one shorter (2.99 Å) and one longer (3.02 Å) Sb–Sb bond lengths.
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