Energy deposition and npFe⁰ initiation for D⁺-irradiated ilmenite. (a) Comparison of npFe⁰ distributions (χ(z)) for 2 hr (blue), 5 hr (green), and 14 hr (purple) with SDTrimSP results. Energy losses to electronic (inelastic, yellow) and nuclear (elastic, green) processes from SDTrimSP are scaled to ﹩{\chi }^{\max }﹩ for the 14 hr exposure to show the depth dependence of energy loss. The implantation profile of D⁺ ions (blue) is also overlaid. (b)–(e) DFT simulation of FeTiO₃. Snapshots showing (b) starting ilmenite lattice, (c) the initial state with the removal of a single O atom (blue circle), and (d) the final state resulting in the formation of an Fe–Fe bond (blue arrow). (e) Fe–O (gold) and Ti–O (gray) distances vs. DFT iteration step.