ERPA: Early Prediction of Adsorbate–Metal Distance Changes on Oxide Surfaces

Can the initial atomic motion, forces, and energy changes reveal how much the adsorbate–metal distance will change by the end of oxide-surface relaxation? We investigate how these early observations predict the absolute initial-to-final adsorbate–metal distance change during density functional theory (DFT) geometry optimization. Adsorbate identity, surface-metal element, material composition, surface orientation, and initial geometry also help predict this change, making the contribution of the early response the central challenge. We introduce Early Relaxation-Path Endpoint Response Analysis (ERPA) to predict this distance-change magnitude from early displacement, force, and energy descriptors, and assess their predictive value against a static-context reference and a geometry-scrambled control. Descriptors use nominal frames 5 and 10 of OC22 trajectories; shorter trajectories contribute their final stored frame. The scrambled control reassigns geometric increments within adsorbate–anchor groups in each split while retaining the recipient's initial, force, and energy descriptors. In processed held-out surface validation on the geometry-screened subset, the paired representation reduces mean absolute error (MAE) by 0.108173 relative to the static reference and by 0.115808 \AA relative to geometry scrambling. Positive static-control gains extend across O, O${}_2$, OH, HO${}_2$, and H${}_2$O. Force-ratio, energy-drop, and distance-change strata connect these gains to recognizable relaxation responses. A separately refitted strict pre-endpoint evaluation uses observations at indices 4 and 9 only for trajectories with at least 11 frames; on 1022 geometry-screened trajectories in processed held-out surface validation, Path reaches MAE 0.259915 \AA, with gains of 0.094553 and 0.097738 \AA against Static and Shuffle, respectively. Together, these comparisons show that a system's own early geometry, force, and energy response supports prediction of its final adsorbate–metal distance-change magnitude before the stored endpoint.