Theoretical structures: superstoichiometric copper-ion intercalated niobium selenide

Few-layer stacked niobium selenide (NbSe2) has evoked great interest owing to its intrinsically exotic properties and accessible manipulation by controlled ion intercalation for superconductivity physics and advanced device applications. However, attempts to extend the range of reversible intercalation stoichiometries are often hindered by overexpanded bond rupture and intrinsic-limit transition metal redox centres in selenides when proceeding towards deep intercalation. Here, we report that reversible unconventional superstoichiometric controlled intercalation in NbSe2 with up to two copper-ions per unit cell can be realized by triggering anionic redox, a fivefold improvement over previous report. Synergistic charge transfer of the transition metal and selenium framework inhibited the disorder of bonds and lattice structures to avoid falling into conversion. This dataset includes the theoretical structures used in the manuscript.