Dataset supporting the publication "Lithium Diffusion in Niobium Tungsten Oxide Shear Structures". Data was generated using the planewave PAW DFT code VASP (www.vasp.at). Results for nudged elastic band (NEB) and ab initio molecular dynamics (AIMD) calculations of lithium are included, for the two compounds Nb12WO33 and Nb14W3O44. The NEB calculations are contained in NEB.zip and grouped into directories that correspond to the different ionic hopping pathways, with the same labelling as in the manuscript text. For file format descriptions, please refer to the README files. For AIMD, the following data is provided: zip files of full trajectories for Li8Nb12WO33 and Li8Nb14W3O44 at temperatures of 700 K, 800 K, 900 K; zip file of the lithium ion probability density distribution in Li5Nb12WO33 and Li8Nb12WO33. More details can be found in the README_AIMD.txt file.