Steric Scaling of Hydrogen Transport in FCC Transition Metals for Mechanically Consistent Molecular Dynamics Simulations
- 1University of Johannesburg , , , ,
Abstract
Hydrogen diffusion in face-centered cubic metals is examined using replicate-resolved molecular dynamics that quantifies temperature-dependent transport and lattice stability. Transport in Ni, Co and Pd is modeled with a hybrid embedded-atom method/Lennard-Jones framework at 800, 900, 1000, and 1250 K. Rather than fitting hydrogen–metal interactions to a single diffusivity, migration energetics are constrained through steric scaling of the FCC interstitial geometry. All baseline finite-concentration parametrizations remain structurally stable under the monitored lattice-volume criteria. Volume fluctuations stay below 0.15% and swelling below 0.09%. Late-time mean-squared displacement remains linear in all accepted trajectories. Four-temperature Arrhenius fits are stable for Ni, Co, and uniform Pd, while scaled Pd remains less constrained. The expected diffusivity hierarchy DPd > DCo ≈ DNi is recovered. Steric scaling lowers Pd diffusivity at every temperature while leaving Ni and Co unchanged, since their interaction parameters are fixed. Pathway-resolved single-H calculations give 0 K barriers of 0.1516 eV for Ni and 0.1294 eV for Co. For Pd, scaling raises the verified static barrier from 0.0234 to 0.0398 eV. A higher-loading Pd test retains the diffusivity reduction while lattice swelling remains bounded. Steric scaling therefore modulates the resolved migration landscape while preserving lattice stability and the observed finite-temperature diffusivity trends.
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BibTeX
@article{tebo2026steric,
title = {{Steric Scaling of Hydrogen Transport in FCC Transition Metals for Mechanically Consistent Molecular Dynamics Simulations}},
author = {Emmanuel Peters-Teke Tebo and Sina Karimzadeh and Nyuytifo Emmanuel Wiykiynyuy and Tien-Chien Jen},
journal = {ACS Omega},
year = {2026},
month = oct,
doi = {10.1021/acsomega.6c05027},
url = {https://pubs.acs.org/acsodf/article/11/42/64724/5451939/Steric-Scaling-of-Hydrogen-Transport-in-FCC},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Steric Scaling of Hydrogen Transport in FCC Transition Metals for Mechanically Consistent Molecular Dynamics Simulations
AU - Emmanuel Peters-Teke Tebo
AU - Sina Karimzadeh
AU - Nyuytifo Emmanuel Wiykiynyuy
AU - Tien-Chien Jen
PY - 2026
DA - 2026/10/15
JO - ACS Omega
DO - 10.1021/acsomega.6c05027
UR - https://pubs.acs.org/acsodf/article/11/42/64724/5451939/Steric-Scaling-of-Hydrogen-Transport-in-FCC
AB - Hydrogen diffusion in face-centered cubic metals is examined using replicate-resolved molecular dynamics that quantifies temperature-dependent transport and lattice stability. Transport in Ni, Co and Pd is modeled with a hybrid embedded-atom method/Lennard-Jones framework at 800, 900, 1000, and 1250 K. Rather than fitting hydrogen–metal interactions to a single diffusivity, migration energetics are constrained through steric scaling of the FCC interstitial geometry. All baseline finite-concentration parametrizations remain structurally stable under the monitored lattice-volume criteria. Volume fluctuations stay below 0.15% and swelling below 0.09%. Late-time mean-squared displacement remains linear in all accepted trajectories. Four-temperature Arrhenius fits are stable for Ni, Co, and uniform Pd, while scaled Pd remains less constrained. The expected diffusivity hierarchy DPd > DCo ≈ DNi is recovered. Steric scaling lowers Pd diffusivity at every temperature while leaving Ni and Co unchanged, since their interaction parameters are fixed. Pathway-resolved single-H calculations give 0 K barriers of 0.1516 eV for Ni and 0.1294 eV for Co. For Pd, scaling raises the verified static barrier from 0.0234 to 0.0398 eV. A higher-loading Pd test retains the diffusivity reduction while lattice swelling remains bounded. Steric scaling therefore modulates the resolved migration landscape while preserving lattice stability and the observed finite-temperature diffusivity trends.
SN - 2470-1343
ER -