Fig. presents calculated lithium-intercalation energies and estimated mean values for each exemplar structure. The fully-ordered all-cis-Ti[O 2 F 4 ] structure has only three non-equivalent interstitial sites, and therefore has a relatively narrow distribution of lithiumintercalation energies, with a mean of -1.53 eV. GApredicted structure 4 is partially disordered, and all 64 cubic interstitial sites in the 4 × 4 × 4 supercell are therefore inequivalent by symmetry. This gives a broader spread in lithium intercalation energies of more than ∼ 1 eV, with an estimated mean of (-2.44 ± 0.05) eV. The SQS structure is, again, more disordered than the GA-predicted structure, and has an even broader spread in lithium intercalation energies (∼ 2 eV) and an estimated mean of (-3.06 ± 0.09) eV.