Systematics and regularity of variation of the properties of A1B3C26 type compounds

Systematization of A1B3C24 compounds by three structure types: derivatives from the structures of ZnS-, NaCl- and TlSe-type, is suggested on the basis of detected regularities of the compound structure variation depending on the value of the ion RA+/RC2-(D) radii; it allows to perform the prediction of structures of non-investigated A1B3C24 compounds. In particular, it is shown that LiGaSe2(Te2), LiInTe2, LiTlS2(Se2, Te2) compounds are to be related to the structure type derivative from ZnS; NaGaS2(Se2), NaTlS2(Se2) - to the structure type derivative from NaCl, and K*GaS2, RbGaS2(Se2Te2), Cs-GaSe2(Te2), RbInSe2(Te2), CsInSe2(Te2), NaTlTe2, KTlSe2(Te2), RbTlSe2(Te2), CsTlSe2(Te2) - to the structure type derivative from TlSe. It is detected that density, melting point, the width of the forbidden zone bear a direct relationship to the sum of atomic numbers of mation of their values for some noninvestigated compounds of the A1B3C24 type is given. Decrease of the values of the melting point and the width of the forbidden zone for the compounds with Σz increase points to weakening of their resistance with increase of formation of coating by chemical conversion of the chemical bond