Rationalization of the Substructures Derived from the Three Fluorite-Related [Li6(MVLi)N4] Polymorphs: An Analysis in Terms of the “Barnighausen Trees” and of the “Extended Zintl–Klemm Concept” - Inorganic 3D Structures - page 113

Table 6 The Barnighausen Tree relating fluorite to CdY 4 Mo 3 O 16

the anion-deficient CdY 4 Mo 3 O 16 -type structure and its Li 7 VN 4 substructure coun-
terpart are of the zinc-blende type, again, a four-connected network!.
Summing up, we have the V(2), Li(2), Li(4) and Li(1) cations of Li 7 VN 4
equating to the cations of CdY 4 Mo 3 O 16 , that is to say the set B cations identified
in our earlier discussion of the zinc-blende-type substructures, and half the anions
of this latter compound (CdY 4 Mo 3 O 16 ) equating to the N(1) and N(2) atoms of
Li 7 VN 4 . The 32 missing cations from Li 7 VN 4 are V(1), Li(3) and Li(5), the same
atoms of the type-A set discussed previously in the context of the zinc-blende-type
substructures. Thus, we can formally describe our Li 7 VN 4 structure as an anion-
deficient CdY 4 Mo 3 O 16 - type structure stuffed with these 32 missing cations: the
substructure formula is Li 26 V 6 N 32 (see Fig. 14 ) .
It is also remarkable that, in CdY 4 Mo 3 O 16 , the 12 Mo atoms form a sodalite-like
cage, as shown in Fig. 15 , just like the Li and V atoms do in

-Li 7 VN 4 (cf. Fig. 9 ) . The
interest is even greater if we take into account that this cage is the result of two

g