{ "snapshot_id": "barrier_prediction_benchmark_2026-04-15", "generated_at_utc": "2026-04-15T00:00:00+00:00", "study_name": "Activation Barrier Prediction — Surface Reactions", "benchmark_mode": "public_production_stack", "description": "Benchmark for the FluxMateria activation-barrier predictor across 29 published surface reactions (N2, H2, O2, CO dissociation and C-H activation) on transition-metal surfaces. Predictions use the Flux Physics barrier route from composition and bond topology, with no per-case DFT input.", "engine_notes": "FluxMateria physics engine. Barriers are predicted from Flux Marcus, bond-order-conservation, and surface descriptor terms, enriched by d-band-center predictions (Hammer-Norskov framework) and Brønsted-Evans-Polanyi linear free-energy corrections for atomic dissociation.", "summary": { "total_cases": 29, "combined_mae_eV": 0.236, "combined_rmse_eV": 0.309, "max_abs_err_eV": 0.923, "within_0p2_eV_pct": 44.8, "within_0p3_eV_pct": 65.5, "within_0p5_eV_pct": 93.1, "fitted_parameters": 0, "training_data_required": false, "dft_inputs_required": false }, "by_reaction_family": [ { "family": "N2_dissociation", "label": "N2 \u2192 2N*", "n": 7, "mae_eV": 0.223, "rmse_eV": 0.252, "max_abs_err_eV": 0.373, "within_0p5_eV_pct": 100.0, "metals_covered": ["Fe", "Ru", "Ni", "Co", "Rh", "Mo", "Re"] }, { "family": "H2_dissociation", "label": "H2 \u2192 2H*", "n": 6, "mae_eV": 0.188, "rmse_eV": 0.218, "max_abs_err_eV": 0.317, "within_0p5_eV_pct": 100.0, "metals_covered": ["Pt", "Pd", "Ni", "Cu", "Ag", "Au"] }, { "family": "O2_dissociation", "label": "O2 \u2192 2O*", "n": 4, "mae_eV": 0.180, "rmse_eV": 0.232, "max_abs_err_eV": 0.419, "within_0p5_eV_pct": 100.0, "metals_covered": ["Pt", "Pd", "Ag", "Cu"] }, { "family": "CH_activation", "label": "CH4 \u2192 CH3* + H* (C-H scission)", "n": 8, "mae_eV": 0.220, "rmse_eV": 0.291, "max_abs_err_eV": 0.601, "within_0p5_eV_pct": 87.5, "metals_covered": ["Ni", "Ru", "Rh", "Pt", "Pd", "Ir", "Co", "Cu"] }, { "family": "CO_dissociation", "label": "CO \u2192 C* + O*", "n": 4, "mae_eV": 0.417, "rmse_eV": 0.535, "max_abs_err_eV": 0.923, "within_0p5_eV_pct": 75.0, "metals_covered": ["Fe", "Ni", "Ru", "Co"] } ], "by_metal_period": [ { "period": "3d (period 4)", "n": 12, "mae_eV": 0.298, "within_0p5_eV_pct": 83.3 }, { "period": "4d (period 5)", "n": 11, "mae_eV": 0.147, "within_0p5_eV_pct": 100.0 }, { "period": "5d (period 6)", "n": 6, "mae_eV": 0.274, "within_0p5_eV_pct": 100.0 } ], "state_of_the_art_comparison": [ { "method": "FluxMateria (this work)", "type": "Flux Physics route, no per-case DFT input", "mae_eV": 0.236, "training_data": "not an ML training route" }, { "method": "PBE DFT (single method)", "type": "Direct DFT", "mae_eV_range": [0.20, 0.30], "training_data": "none (full DFT per case)" }, { "method": "RPBE DFT (single method)", "type": "Direct DFT", "mae_eV_range": [0.20, 0.30], "training_data": "none (full DFT per case)" }, { "method": "BEEF-vdW DFT", "type": "Direct DFT", "mae_eV_range": [0.15, 0.25], "training_data": "none (full DFT per case)" }, { "method": "BEP scaling relations (N\u00f8rskov)","type": "Analytical on DFT fit", "mae_eV_range": [0.20, 0.30], "training_data": "DFT database" }, { "method": "Hammer-N\u00f8rskov analytical", "type": "Analytical", "mae_eV_range": [0.30, 0.50], "training_data": "DFT database" }, { "method": "UBI-QEP (Shustorovich)", "type": "Analytical", "mae_eV_range": [0.30, 0.60], "training_data": "experimental fit" }, { "method": "SISSO surrogate", "type": "ML on DFT features", "mae_eV_range": [0.20, 0.30], "training_data": "~10^3 DFT points" }, { "method": "CGCNN / GemNet-OC / Equiformer", "type": "Graph neural networks", "mae_eV_range": [0.15, 0.25], "training_data": "~10^5\u201310^6 DFT points" }, { "method": "MACE / M3GNet foundation MLFF", "type": "Universal ML force field", "mae_eV_range": [0.10, 0.20], "training_data": "~10^6\u201310^7 DFT points" } ], "literature_benchmark_cases": [ { "reaction": "N2 \u2192 2N* on Fe(110)", "E_a_exp_eV": 0.90, "E_a_pred_eV": 0.573, "source": "Logadottir 2001" }, { "reaction": "N2 \u2192 2N* on Ru(0001)", "E_a_exp_eV": 0.40, "E_a_pred_eV": 0.312, "source": "Logadottir 2001" }, { "reaction": "N2 \u2192 2N* on Ni(111)", "E_a_exp_eV": 1.85, "E_a_pred_eV": 1.497, "source": "Vojvodic 2011" }, { "reaction": "N2 \u2192 2N* on Co(0001)", "E_a_exp_eV": 1.41, "E_a_pred_eV": 1.539, "source": "Logadottir 2001" }, { "reaction": "N2 \u2192 2N* on Rh(111)", "E_a_exp_eV": 1.19, "E_a_pred_eV": 1.403, "source": "Bligaard 2004" }, { "reaction": "N2 \u2192 2N* on Mo(110)", "E_a_exp_eV": 0.19, "E_a_pred_eV": 0.114, "source": "Logadottir 2001" }, { "reaction": "N2 \u2192 2N* on Re(0001)", "E_a_exp_eV": 0.64, "E_a_pred_eV": 0.267, "source": "Bligaard 2004" }, { "reaction": "H2 \u2192 2H* on Pt(111)", "E_a_exp_eV": 0.04, "E_a_pred_eV": 0.010, "source": "Tkatchenko 2008" }, { "reaction": "H2 \u2192 2H* on Pd(111)", "E_a_exp_eV": 0.05, "E_a_pred_eV": 0.253, "source": "Greeley 2009" }, { "reaction": "H2 \u2192 2H* on Ni(111)", "E_a_exp_eV": 0.08, "E_a_pred_eV": 0.142, "source": "Greeley 2009" }, { "reaction": "H2 \u2192 2H* on Cu(111)", "E_a_exp_eV": 0.50, "E_a_pred_eV": 0.817, "source": "Michaelides 2005" }, { "reaction": "H2 \u2192 2H* on Ag(111)", "E_a_exp_eV": 1.10, "E_a_pred_eV": 0.896, "source": "N\u00f8rskov 2014" }, { "reaction": "H2 \u2192 2H* on Au(111)", "E_a_exp_eV": 1.05, "E_a_pred_eV": 0.739, "source": "N\u00f8rskov 2014" }, { "reaction": "O2 \u2192 2O* on Pt(111)", "E_a_exp_eV": 0.36, "E_a_pred_eV": 0.779, "source": "Eichler 1999" }, { "reaction": "O2 \u2192 2O* on Pd(111)", "E_a_exp_eV": 0.40, "E_a_pred_eV": 0.247, "source": "N\u00f8rskov 2014" }, { "reaction": "O2 \u2192 2O* on Ag(111)", "E_a_exp_eV": 0.50, "E_a_pred_eV": 0.480, "source": "Campbell 1985" }, { "reaction": "O2 \u2192 2O* on Cu(111)", "E_a_exp_eV": 0.20, "E_a_pred_eV": 0.073, "source": "N\u00f8rskov 2014" }, { "reaction": "CH4 \u2192 CH3* + H* on Ni(111)", "E_a_exp_eV": 1.02, "E_a_pred_eV": 0.613, "source": "Bengaard 2002" }, { "reaction": "CH4 \u2192 CH3* + H* on Ru(0001)", "E_a_exp_eV": 0.72, "E_a_pred_eV": 0.613, "source": "Chin 2011" }, { "reaction": "CH4 \u2192 CH3* + H* on Rh(111)", "E_a_exp_eV": 0.68, "E_a_pred_eV": 0.613, "source": "Bengaard 2002" }, { "reaction": "CH4 \u2192 CH3* + H* on Pt(111)", "E_a_exp_eV": 0.85, "E_a_pred_eV": 1.069, "source": "Bengaard 2002" }, { "reaction": "CH4 \u2192 CH3* + H* on Pd(111)", "E_a_exp_eV": 0.78, "E_a_pred_eV": 0.765, "source": "Bengaard 2002" }, { "reaction": "CH4 \u2192 CH3* + H* on Ir(111)", "E_a_exp_eV": 0.55, "E_a_pred_eV": 0.841, "source": "Bengaard 2002" }, { "reaction": "CH4 \u2192 CH3* + H* on Co(0001)", "E_a_exp_eV": 1.10, "E_a_pred_eV": 0.499, "source": "Vojvodic 2011" }, { "reaction": "CH4 \u2192 CH3* + H* on Cu(111)", "E_a_exp_eV": 1.50, "E_a_pred_eV": 1.444, "source": "N\u00f8rskov 2014" }, { "reaction": "CO \u2192 C* + O* on Fe(110)", "E_a_exp_eV": 1.70, "E_a_pred_eV": 1.695, "source": "Bligaard 2004" }, { "reaction": "CO \u2192 C* + O* on Ni(111)", "E_a_exp_eV": 2.80, "E_a_pred_eV": 1.877, "source": "Andersson 2008" }, { "reaction": "CO \u2192 C* + O* on Ru(0001)", "E_a_exp_eV": 2.03, "E_a_pred_eV": 1.558, "source": "Andersson 2008" }, { "reaction": "CO \u2192 C* + O* on Co(0001)", "E_a_exp_eV": 1.68, "E_a_pred_eV": 1.948, "source": "N\u00f8rskov 2014" } ], "literature_sources": [ { "citation": "Logadottir A., Rod T.H., N\u00f8rskov J.K. et al., J. Catal. 197, 229 (2001)" }, { "citation": "Bligaard T., N\u00f8rskov J.K., Dahl S. et al., J. Catal. 224, 206 (2004)" }, { "citation": "Vojvodic A., N\u00f8rskov J.K., Science 334, 1355 (2011)" }, { "citation": "Bengaard H.S., N\u00f8rskov J.K. et al., J. Catal. 209, 365 (2002)" }, { "citation": "Chin Y.H., Buda C., Neurock M., Iglesia E., J. Am. Chem. Soc. 133, 15958 (2011)" }, { "citation": "Andersson M.P., Abild-Pedersen F., N\u00f8rskov J.K., J. Catal. 255, 6 (2008)" }, { "citation": "Eichler A., Hafner J., Surf. Sci. 433-435, 58 (1999)" }, { "citation": "Campbell C.T., Surf. Sci. 157, 43 (1985)" }, { "citation": "Michaelides A., Scheffler M. et al., J. Am. Chem. Soc. 127, 6289 (2005)" }, { "citation": "Tkatchenko A. et al., Phys. Rev. Lett. 101, 073005 (2008)" }, { "citation": "Greeley J., Stephens I.E.L., Bondarenko A.S. et al., Nat. Chem. 1, 552 (2009)" }, { "citation": "N\u00f8rskov J.K. et al., 'Fundamental Concepts in Heterogeneous Catalysis', Wiley (2014)" } ], "known_limitations": [ "CO dissociation on Ni under-predicted by ~0.9 eV: Ni's magnetic coupling to CO fragments is beyond the d-band-center framework.", "CH4 activation on Co under-predicted: the shallow-d-band clamp on the activation floor is conservative.", "3d transition metals show slightly higher residuals than 4d (which hits 0.147 eV MAE). The 4d series is where d-band-center predictions are cleanest.", "O2 dissociation on Pt hits a bond-breaking-floor intrinsic to Marcus-type formulations.", "The benchmark covers transition-metal (111), (110), (0001) surfaces; step/kink corrections are a separate layer." ], "use_case_readiness": { "catalyst_screening_and_ranking": "production-ready", "inverse_search_and_candidate_discovery": "production-ready", "qualitative_activity_classification": "production-ready", "reaction_family_ranking": "production-ready", "trend_prediction_across_metal_series": "production-ready", "quantitative_tof_prediction": "edge-of-usefulness (MAE target < 0.1 eV)", "selectivity_between_close_mechanisms": "edge-of-usefulness (< 0.1 eV needed)", "transition_state_geometry": "not applicable (analytical barrier only)" } }