Vacancy Configuration Effects on Oxygen–Carbon Bonding and Carbon Network Reconstruction in Fullerene Nanocages

ReaxFF molecular dynamics was used to examine oxygen–carbon bonding and carbon network reconstruction of pristine C60, monovacancy C59, and two specific C58 vacancy configurations at 1600-2800 K. Oxidation and oxygen-free conditions each used three independent trajectories and 200 ps production periods. At 2800 K and nominal oxygen loading of 0.5, the normalized C–O bond order sums were 0.04075 ± 0.03532 for V2-adj and 0.17501 ± 0.04520 for V2-sep. Their initial C–C retention fractions were 0.9617 ± 0.0397 and 0.6231 ± 0.1279, respectively. These late-stage differences persisted across bond order thresholds of 0.30–0.40. Matched oxygen-free controls showed substantial thermal reconstruction, especially for V1, demonstrating that connectivity replacement cannot generally be attributed to oxygen attack. The V2-sep mean was 7.85% below an additive two-V1 bonding benchmark, but the difference was smaller than its propagated sampling uncertainty. The results concern the selected configurations and parametrization, whose initial coordination environments differ; they do not establish universal vacancy separation effects or real soot oxidation kinetics.