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Supporting Information: Structural evolution of titanium dioxide during reduction in high-pressure hydrogen

Summary

This wiki entry registers the Supporting Information PDF (papers/ReaxFF_others/Selcuk_Selloni_NatureMaterials_2018_TiO2_H2_SI.pdf) for Selcuk, Zhao, and Selloni, Nature Materials DOI 10.1038/s41563-018-0135-0. The parent article investigates structural evolution of titanium dioxide during reduction in high-pressure hydrogen using multiscale modeling that includes ReaxFF reactive MD; the SI package is not a standalone research article but provides validation material that underpins the reactive simulations. Corpus extracts emphasize ReaxFF versus DFT/DFT+U comparisons for hydrogen diffusion on anatase surfaces—illustrative potential-energy profiles for surface-to-subsurface hopping appear in supplementary figures referenced from the main text.

Methods

Per the SI structure, validation follows pathways and coordinate definitions consistent with the main article and prior DFT literature on TiO₂ surfaces: ReaxFF energy profiles are compared against DFT and DFT+U references along representative H migration coordinates on selected anatase facets. These static profiles complement the nanosecond-scale reactive trajectories reported in the primary publication by demonstrating that the force field recovers key barrier shapes needed for qualitative transferability in H₂ reduction simulations.

Linked production MD (parent article). For the reactive molecular dynamics used in the peer-reviewed study, see 2018selcuk-nat-structural-evolution: LAMMPS ReaxFF simulations on anatase slabs/nanoparticles in high-pressure H\(_2\) (e.g. 800 K, 200 bar, NPT-style stress control with Nosé–Hoover thermostat/barostat, 0.1 fs timestep, ~1 ns (nanosecond) production segments as reported there). PBC: three-dimensional periodic supercells. Electric field / enhanced sampling: N/A — not used in the protocol description excerpted for this SI landing page.

SI-only limitations on this file. The corpus extract for this Supporting Information PDF is thin (Fig. S1 header + caption); N/A — full supercell stoichiometries, k-mesh settings, and additional facet benchmarks must be read from the complete SI PDF and the main article.

Findings

The excerpted SI material supports qualitative alignment between ReaxFF and higher-level electronic-structure calculations along the illustrated H diffusion coordinates, strengthening the case that the reactive MD captures the correct hopping hierarchy for the modeled reduction context. Full numerical barriers, convergence settings, and additional facet comparisons must be read from the complete SI PDF and the main article; this wiki page should not be treated as a substitute for those tables.

Limitations

The corpus extraction_quality is partial; figures beyond the excerpt may contain additional benchmarks. Always use [[2018selcuk-nat-structural-evolution]] for the peer-reviewed narrative and citation strings.

Reproducibility notes

When using SI energy profiles to justify production ReaxFF runs, archive the DFT functional, hubbard U choices (if any), and k-point settings used for the reference curves, because DFT+U sensitivity can shift barrier heights independently of ReaxFF quality. For H diffusion on anatase, pathway labels should match the facet and hopping coordinate definitions in the SI figures to avoid mixing distinct surface sites.

Because this corpus extract is partial, operators should not assume the SI contains only the single profile excerpted here: additional facets, coverages, or convergence studies may exist later in the PDF and should be consulted before claiming “full” validation coverage. If SI figures include multiple hopping pathways, ensure the production MD uses the same rate-limiting step identified by the lowest barrier in the benchmark set.

Relevance to group

Documents benchmark-quality comparisons underpinning ReaxFF application to TiO2 hydrogenation.

Citations and evidence anchors