My blog in italian on this topics is very popular and for this reason I decided to add an English translation (when I have some free time, I will also translate the text in the Figure and Table). So be tune and more will come!
The stability of a crystal lattice at constant T and P conditions is linked to the Gibbs free energy of lattice formation by the relations
If is more negative for the formation of the
structure than for the
structure, the
transition will be spontaneous and the solid will have that structure.