In the calculation of electrochemical reaction energetics using GGA-DFT, it is frequently implicitly assumed that ions in the Helmholtz plane have unit charge. However, the ion charge is observed to be fractional near the interface through both a capacitor model and through Bader charge partitioning. In this work, we show that this spurious charge transfer can be effectively mitigated by continuum charging of the electrolyte. We then show that, similar to hydronium, the observed fractional charge of hydroxide is not due to a GGA level self-interaction error, as the partial charge is observed even when using hybrid level exchange–correlation functionals.
Joseph A. Gauthier, Leanne D. Chen, Michal Bajdich and Karen Chan
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Volume: 22 Issue: 13 Pages: 6964-6969
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