Comprehensive studies have been undertaken, inclusive of experimental and computational techniques, on the structure and cation distribution of spinel solid solutions formed between the normal spinel LiMn 2O 4 and inverse LiFe 5O 8. Series of solid solutions of a composition (1− x)LiMn 2O 4 · xLi 0.5Fe 2.5O 4 are single phase products with spinel structure in the whole range of x, displaying a cubic structure. With increasing Fe 3+ content, the tendency of ordering by lithium ions in octahedral spinel sites and a strongly marked preference of Li + cations to occupy the octahedral positions is apparent. Modelling and refinement of crystal structure of such spinel solid solution series have been undertaken by the energy minimisation procedure, together with the interatomic potentials calculation, explaining some divergences of the experimental data.