T1A1F4-Type Octahedral Coordination about Me

The structure of this type was elucidated in the compound TIAIF4 by Brosset 51) and later observed also in alkali compounds AAIF4 (A = K, 

Rb) (52). According to new work of Garion and Wanklyn [107) the corresponding ternary aluminium fluorides of Lithium and Natrium show a superstructure of this type. 

Ternary transition metal fluorides of the TlAlF4-t37pe seem to exist in NH4SCF4 [124), in RbCrF4 and RbFeF4 [8). The two Rb-compounds mentioned, however, possibly crystallize in a superstructure of the TlAlF4-type. The lattice constants of the unimolecular unit cells are listet in Table 20 together with some further isostructural Al-compounds (52). 

The powder diagrams of the ternary mangan(III)-fluorides LiMnF4 [163) KMnF4 and RbMnF4 [166) could not be indexed yet. Possibly the Jahn-Teller distortion not only affects the MnFe --octahedra, but also the symmetry of the unit cells, which, at least in the case of the potassium-and rubidium-compounds, should be very similar to each other. 

2) Compounds AMep4 with Coordination Numbers other than 6 

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