"Meta" - dessignates"  that the extent of similarity (that is: at some conditions the compound may be similar to the "reference compound") but if conditions are changed - it undergo transformation - for example like polimorphism;;;;  the extent of stability under given conditions. The Chemistry could remain the same.

Regards,  Leonid

I think means the compound consist from hybrid material or semi

material 

Dear Dr.  Zulueta:

The most general idea of prefixes is provide a clear concept of sequence or hierarchical level, in which some parameter indicates position or a number. In fact, the application of prefixes is case sensitive. At inorganic chemistry can be applied to determine the number of water molecules with relation to the anhydride compounds. At organic chemistry, prefixes indicate positions of a specific bound of a radical from a specific position in the molecule. There are other applications of prefixes.

Most frequently, for oxides, prefixes stemming of the necessity of provides information at about stoichiometry in polycation compounds or sometimes the number of determined cationic specie in the unitary cell. The existence of number of prefixes should occur always that several compounds or oxides exist in a complex sequence from a simplest member. Seems that niobates can give a significant set of examples, with three major groups.

The META prefix is used to specify the first member of a serie or sequence of compounds with two or more members.

The prefix Meta is applied in niobates polycation ternaries, as an example the metaniobates with stoichiometric relation 1:1: as: LiNbO3. NaNbO3 and KNbO3. For niobates with stoichiometric relation distinct of 1:1, such as 3:1 the prefix adopted is ORTHO, as an example it is possible to make mention to orthoniobates: Na3NbO4 and K3NbO4. The existence of several cations of interest in the formula can be also reported in stoichiometries with ratio 8:6, as in K8Nb6O19 termed Hexaniobate, prefix HEXA indicating six niobium cations in the formula.

In above sense, Metatitanates exhibits relation M:Ti equal to 1:1. Orthotitanates represents titanates with relation M:Ti equal to 2:1.

Best regards

Marcos Nobre

Many thanka for your pront anwer. So no mather barium meta titanate and barium titanate 

No. You have not understood Joachim's answer correctly. There is a structural and a difference in the number of atoms. Possibly the example of ortho- and Meta-phosphoric acid helps to understand the difference. Meta is the unhydrid of the phosphoric acid. I have a formula within the manuscript describing the water equilibr

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