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41 changes: 25 additions & 16 deletions input/thermo/libraries/CO2RR_Adsorbates_Ag111.py
Original file line number Diff line number Diff line change
Expand Up @@ -5,24 +5,33 @@
solvent = "water"
shortDesc = u"CO2RR adsorbate thermochemistry on Ag(111) from DFT"
longDesc = u"""
NASA polynomial thermochemistry for C1 and C2 adsorbate intermediates
relevant to electrochemical CO2 reduction (CO2RR) on Ag(111).
Adsorbates are labeled with a trailing or interleaved 'X' to indicate
surface binding sites, per RMG conventions.
This library contains NASA polynomial thermochemistry for adsorbate
intermediates relevant to electrochemical CO2 reduction (CO2RR) on the
Ag(111) surface. All adsorbates are denoted with a trailing 'X' (or
interleaved 'X' for bidentate species) to indicate surface binding sites,
consistent with RMG conventions.

DFT (Manish Kumar Kothakonda, Northeastern): VASP with PBE + Grimme D3
zero-damping (IVDW = 12) and PAW pseudopotentials.
A two-stage protocol was used:
Initial geometries were pre-optimized at ENCUT = 400 eV with a 3x3x1
Monkhorst-Pack k-mesh, then fully re-relaxed to force convergence at
tighter settings of ENCUT = 500 eV and 4x4x1 k-mesh (IBRION = 2,
EDIFFG = -0.03 eV/A). All final energies - adsorbate slabs, bare-slab
reference, and vibrational frequencies - were computed at the tight
settings.
DFT calculations were performed by Manish Kumar Kothakonda (Northeastern University).
Geometry optimization of adsorbates on a periodic Ag(111) slab.
Calculations used VASP 6.3.1 with the PBE exchange-correlation functional,
Grimme D3 zero-damping dispersion correction (IVDW = 12), and PAW
pseudopotentials. Plane-wave cutoff ENCUT = 500 eV; 3x3x1 Gamma-centered
Monkhorst-Pack k-point mesh; Methfessel-Paxton smearing (ISMEAR = 1,
SIGMA = 0.10 eV); spin-polarized (ISPIN = 2); SCF convergence
EDIFF = 1E-6 eV; ionic force convergence EDIFFG = -0.03 eV/A
(IBRION = 2). The slab is a hexagonal Ag(111) supercell with lattice
parameters a = b = 11.506 A, c = 31.046 A (cell volume 3559.27 A^3),
containing 64 Ag atoms arranged in 4 atomic layers; the bottom 3 layers
were held fixed (F F F) while the top layer plus adsorbate atoms were
allowed to relax (T T T). Implicit solvation in water was applied via
VASPsol. Harmonic vibrational frequencies were computed using finite-difference
displacements (IBRION = 5, NFREE = 2, POTIM = 0.015 A) on the relaxed
atoms (adsorbate plus top slab layer).

Post-processing and thermo (Su Sun) via the Westgroup pipeline
(adapted from input_generator.py and compute_NASA_for_adsorbates): VASP
outputs converted to ASE .traj and inspected; vibrational frequencies
Post-processing and stat thermo calculations were performed by
Su Sun (Northeastern University) via the Westgroup pipeline
(adapted from input_generator.py and compute_NASA_for_adsorbates):
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Would be good to mention where these files are, if they are version controlled somewhere

VASP outputs converted to ASE .traj and inspected; vibrational frequencies
and ZPEs consolidated into per-species zpe_log_<species>.txt files;
imaginary modes replaced with 12 cm^-1. Heat of formation at 0 K was
computed from a thermochemical cycle against CH4, H2O, and H2 references
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