II. EPR of Mn²⁺ in the three ferroelectric phase of Zn-Cl boracite, a model for the monoclinic phase with a bigger cell is proposed

An important question concerning the structure of trigonal boracites is whether the metal sites are all of type "1" or all of type "2,3" or a mixture of both (see Figure 1 of our paper I, this conference). Another important one concerns the structure of the monoclinic phase of boracites. In this case only the lattice parameters of the Fe-I composition have been determined.