| name | catgo-gibbs-pipeline |
| description | Compute adsorption/reaction Gibbs free energies, free-energy diagrams, and electrochemical overpotentials (HER/ORR/OER/CO2RR/NRR) with VASP. The per-species pipeline is geo_opt → freq → Gibbs; CHE references; ΔG → η. Use whenever a study's target is a FREE energy (not raw DFT energy) — overpotential, free-energy diagram, ΔG of adsorption/reaction, limiting potential. Pairs with the catgo-campaign skill for orchestration. |
catgo-gibbs-pipeline — adsorption/reaction free energies & overpotential
TL;DR: G = E_DFT + ZPE − TΔS. Every species in a ΔG needs geo_opt and freq.
Per-species pipeline: geo_opt → freq → Gibbs; assemble ΔG → η.
When to use
Any study whose target is a free energy — overpotential η, free-energy diagram, ΔG of
adsorption/reaction, limiting potential (HER/ORR/OER/CO2RR/NRR, adsorption thermo). Raw
geo_opt energies are NOT enough: add ZPE + TΔS from frequencies.
Core rules (the why)
- Free energy needs freq. Skipping freq gives wrong ΔG and wrong η.
- Per species, pipeline not barrier. Each species' freq fires as ITS geo_opt
converges — don't wait for siblings, don't wait for a reminder.
- Convergence by force, not dE:
FORCES: max atom < |EDIFFG|.
- CHE, not O2: G(H⁺+e⁻)=½G_H2; derive O/OH from H2O+H2; never compute O2.
- Gas refs cheap: Γ-only +
vasp_gam on shared; slabs vasp_std + k-mesh on compute.
Bundled resources
catgo freq-inputs — build a VASP freq input from a relaxed CONTCAR/POSCAR
(adsorbate: fix surface, free adsorbate atoms; gas: all free). Runs from ANY directory:
catgo freq-inputs --structure <CONTCAR> --out <dir> [--gas | --free-elements O,H].
Wraps scripts/build_freq_inputs.py (call the script directly only if catgo isn't on
PATH; resolve it as <this skill base>/scripts/build_freq_inputs.py, never a hardcoded
~/.claude/... path).references/method.md — full thermo + freq setup + CHE/ORR/OER/HER pathway formulas +
the η definition. Read for the exact equations.examples/orr-pt111.md — a worked ORR-on-Pt(111) instance (build freq, assemble η).
Flow
- geo_opt each species (force-converged) → E.
catgo freq-inputs from each CONTCAR → submit freq → catgo freq --mode adsorbed|gas
→ ZPE + TΔS → G.- Assemble ΔG_i along the pathway → U_L = max ΔG_i/e → η = |1.23 − U_L|; free-energy
diagram + ΔG table. (Building blocks: the
vasp-freq, gibbs, her, oer,
energy-diagram skills.)
In a CatGo campaign, wire this into plan.md and let the loop fire freq per species — see
the catgo-campaign + catgo-campaign-loop skills.
