Structural deformations in lithium doped titanium dioxide

Density functional simulations of lithium intercalation into rutile structured titanium dioxide are presented. Full relaxation of structures for a wide range of insertion concentrations is used to identify the thermodynamically most stable configurations. The host lattice is found to undergo large deformations upon Li-insertion which can be related to the excitation of soft vibrational modes. The dominant screening interaction is found to be due to these elastic distortions of the lattice rather than to dielectric screening.