Simulations were carried out in order to investigate local structural disorder in LiMn2O4 spinel. Small but significant shifts in lithium and oxygen atom positions from the high symmetry sites of the Fd3̄m lattice were observed. The lithium atoms were displaced approximately 0.16Å away from the 8a site of the Fd¯3m lattice and were shifted, along the diffusion pathway, towards the face mid-points of the coordinating LiO4 tetrahedra. A diffuse population of Li atoms was also detected which was centered about 0.38Å away from the 16c octahedral vacancy; suggesting that some of the Li atoms were free from their tetrahedral cages at room temperature. The tetrahedrally coordinated O atoms were displaced by as much as 0.12Å when bonded to one Li and three Mn atoms in identical oxidation states. If the coordinating Mn atoms were in mixed oxidation states, much larger O atom shifts of 0.22Å were observed. Structural features obtained in this simulation, especially the off-center displacements of Li and O atoms, were in accord with electron density distribution studies of cubically stabilized Mg-doped LiMn2O4 spinel.

Structural Disorder Along the Lithium Diffusion Pathway in Cubically Stabilized Lithium Manganese Spinel II. Molecular Dynamics Calculation. Tateishi, K., Du Boulay, D., Ishizawa, N., Kawamura, K.: Journal of Solid State Chemistry, 2003, 174[1], 175-81