Structure elements of a solid

Because of all these peculiarities, the description of a solid simply through the lens of its atoms, ions or molecules cannot give an 

Thermodynamic Modeling of Solid Phases, First Edition. Michel SousteUe. ISTE Ltd 2015. Published by ISTELtd and John Wiley Sons, Inc. 

A structure element is an atom, an ion or a vacancy (an empty space) at a specific site in the crystal. The concept of a structure element brings together that of a chemical species and that of its environment by the nature of the crystalline site in question. A structure element could be  

we can completely describe the solid by enumerating its stmcture elements, assimilating the fiee electrons and the electron holes likely to be present to structure elements, for the sake of 

The structure elements can carry different charges. The effective charge of a structure element, denoted by qe, is the difference between its real charge, represented by qr, and the charge that the structure element occupying the same site in the ideal crystal would have, or the normal charge , denoted by qni 

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For the chemical potential (and for all the partial molar values) of a structure element, we again find the same difficulty as encountered in the case of ions. Indeed, it is impossible to maintain the quantities of elements for all types of structure elements of a solid, except for one of them because, in addition, the electrical neutrality but also the ratios between sites must be preserved in a transformation. In order to circumvent the difficulty, we use the same approach as with the ions,... 

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