G interstitial anion of MG

This reaction also occurs in a sohd containing M and refers to reaction [2.R.17], written from right to left. This consumption involves two jumps and therefore two 

The voluminal speed of this elementary step can be written as (defects being 

It should be noted that the second phase, as well as the whole process, creates a new MG building unit and thus increases the size of the solid formed. 

The two preceding steps include an equivalent reaction (see section 7.9) that can be written as  

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