Madelung energies and cation distributions in olivine-type structures

Madelung energies of 16 olivine-type structures of phosphates, silicates, borates and beryllates were computed for varying charges in sites M(1) and M (2). Predictions on the distributions of cations in sites M(1) and M(2) made on the basis of such energy calcns., agree with all the refinements published so far for structures of the olivine-type. The calcns. indicate a lower Madelung energy for ordered cations. Site preferences of many elements in olivine-type structures are predicted