DOI: 10.17877/resolv-2025-mffc7vm3
title: Source data: Distinct solvation patterns of OH− versus H3O+ charge defects at electriﬁed gold/water interfaces govern their properties

description: This project studies the distinct solvation structures of H3O+ and OH− ions on electrified gold surfaces.This is the source data used for the paper: "Distinct solvation patterns of OH– versus H3O+ charge defects at electrified gold/water interfaces govern their properties".
This dataset is meant to give access to the source data for other researchers to enable comparison and further research into this topic.&lt;br /&gt; 
&lt;br /&gt;
Understanding the solvation structures of OH– and H3O+ at metal interfaces is crucial for developing efficient electrochemical devices. In this paper, we present a detailed investigation of the solvation structures of OH– and H3O+ near gold electrodes under alkaline and acidic aqueous conditions, using ab initio molecular dynamics simulations at controlled surface charge density conditions. Our findings reveal that the adsorption
tendencies of OH– and H3O+ are strongly influenced by the oscillating net atomic charge of water normal to the electrified interface in concert with the distinct solvation patterns of these charge defects. While OH– preferentially adsorbs onto the gold surface within the first water layer, the positive net atomic charge restricts the closest
approach of H3O+ to beyond the first water layer. We unveil resting and active states that support charge transfer processes at the gold/water interface which critically involve Au atoms in a unique Grotthuss-like mechanism.
description: The contents of the columns in the data files are described as follows:<br>
<br>
<b>Charge migration of the H3O+ and OH- charge defects</b><br>
data/fig1/panel_c/oh_pos_naoh.dat<br>
data/fig1/panel_c/Fig1/panel_c/oh_pos_naoh.dat<br>
First column; Second column = Time(ps); Position (Angstrom)<br>
<br>
<b>Density profiles for acidic aqueous electrolytes at Au interfaces</b><br>
data/fig1/panel_d/hclo4_vm3_mass_density_O.dat<br>
data/fig1/panel_d/hclo4_vm3_mass_density_H.dat<br>
data/fig1/panel_d/hclo4_v0_mass_density_O.dat<br>
data/fig1/panel_d/hclo4_v0_mass_density_H.dat<br>
data/fig1/panel_d/hclo4_vm3_mass_density_h3o.dat<br>
First column; Second column = Position z (Angstrom); Density \rho (kg L^-1)<br>
<br>
<b>Density profiles for alkaline aqueous electrolytes at Au interfaces</b><br>
data/fig1/panel_e/naoh_v1_mass_density_oh.dat<br>
data/fig1/panel_e/naoh_v1_mass_density_O.dat<br>
data/fig1/panel_e/naoh_v1_mass_density_H.dat<br>
data/fig1/panel_e/naoh_v0_mass_density_O.dat<br>
data/fig1/panel_e/naoh_v0_mass_density_H.dat<br>
First column; Second column = Position z (Angstrom); Density \rho (kg L^-1)<br>
<br>
<b>Orientations of H3O+(Eigen, panel a), H3O+(Zundel, panel b), and OH-</b><br>
data/fig2/panel_a_oh_vector_h3o_pzc.dat<br>
data/fig2/panel_a_oh_vector_h3o_vm3.dat<br>
data/fig2/panel_b_zundel_vector_pzc.dat<br>
data/fig2/panel_b_zundel_vector_vm3.dat<br>
data/fig2/panel_c_OH_vector_pzc.dat<br>
data/fig2/panel_c_OH_vector_v1.dat<br>
First column; Second column = Angle cos(\theta); Probability<br>
<br>
<b>Radial distribution functions of H3O+ and water</b><br>
data/fig3/panel_a/rdf_h3o_bl_pzc.dat<br>
data/fig3/panel_a/rdf_h3o_bl_vm3.dat<br>
data/fig3/panel_a/rdf_h3o_if_pzc.dat<br>
data/fig3/panel_a/rdf_h3o_if_vm3.dat<br>
data/fig3/panel_a/rdf_Owater_Owater_hclo4_vm3_if.dat<br>
First column; Second column = Distance r (Angstrom); Radial distribution function g(r)<br>
<br>
<b>Radial distribution functions of OH- and water</b><br>
data/fig3/panel_b/rdf_if_pzc.dat<br>
data/fig3/panel_b/rdf_if_v1.dat<br>
data/fig3/panel_b/rdf_oh_bl_pzc.dat<br>
data/fig3/panel_b/rdf_oh_bl_v1.dat<br>
data/fig3/panel_b/rdf_Owater_Owater_naoh_v1_if.dat<br>
First column; Second column = Distance r (Angstrom); Radial distribution function g(r)<br>
<br>
<b>Distribution function of the distance between O*-O\tilde and Au*-Au\tilde in bulk-like (BL) and interface (IF)</b><br>
data/fig3/panel_c/dist-ostar-otilde-if.dat<br>
data/fig3/panel_c/dist-ostar-otilde-bl.dat<br>
data/fig3/panel_c/dist-austar-autilde.dat<br>
data/fig3/panel_c/dist-au-au-resting.dat<br>
First column; Second column = Distance r (Angstrom); Probability<br>
<br>
<b>Free energy profiles along the charge transfer coordinate for H3O+in BL and IF</b><br>
data/fig3/panel_d/freeE_h3o_if_vm3.dat<br>
data/fig3/panel_d/freeE_h3o_if_pzc.dat<br>
data/fig3/panel_d/freeE_h3o_bl_vm3.dat<br>
data/fig3/panel_d/freeE_h3o_bl_pzc.dat<br>
First column; Second column = Charge transfer coordinate δ (Angstrom); ∆Free energy (kcal mol^-1)<br>
<br>
<b>Free energy profiles along the charge transfer coordinate for OH- in BL and IF</b><br>
data/fig3/panel_e/freeE_oh_if_v1.dat<br>
data/fig3/panel_e/freeE_oh_if_pzc.dat<br>
data/fig3/panel_e/freeE_oh_bl_v1.dat<br>
data/fig3/panel_e/freeE_oh_bl_pzc.dat<br>
First column; Second column = Charge transfer coordinate δ (Angstrom); ∆Free energy (kcal mol^-1)<br>
<br>
<b>The density profiles of H3O+ and OH-</b><br>
data/fig4/panel_a/rho_oh.dat<br>
data/fig4/panel_a/rho_h3o.dat<br>
First column; Second column = Position z (Angstrom); Density \rho (kg L^-1)<br>
<br>
<b>Excess charge profile for OH- and H3O+</b><br>
data/fig4/panel_a/deltaq_neat_water.dat<br>
data/fig4/panel_a/oh_if.dat<br>
data/fig4/panel_a/oh_bl.dat<br>
data/fig4/panel_a/h3o_bl.dat<br>
data/fig4/panel_a/h3o_if.dat<br>
data/fig4/panel_a/deltaq_hclo4.dat<br>
data/fig4/panel_a/deltaq_naoh.dat<br>
First column; Second column = Position z (Angstrom); Net atomic charge (NAC) (e)<br>
<br>
<b>Excess charge profile for OH- and Au* depending on the hydrogen bonding state</b><br>
data/fig4/panel_b/nac_oh.dat<br>
data/fig4/panel_b/nac_austar.dat<br>
First column; Second column = <br>
D1A4; Net atomic charge (e) <br>
D1A3-perpendicular; Net atomic charge (e) <br>
D1A3-parallel; Net atomic charge (e) <br>
D1A2; Net atomic charge (e)<br>
<br>
<b>Average number N of donor (D) and acceptor (A) HBs of OH-</b><br>
data/fig4/panel_c/hb_otilde.dat<br>
data/fig4/panel_c/hb_otilde_austar.dat<br>
First column; Second column =<br>
Resting Donor; Number (N)<br>
Resting Acceptor; Number (N)<br>
Active Donor; Number (N)<br>
Active Acceptor; Number (N)<br>
<br>
<b>Distribution function of the NAC O*, O\tilde, O (BL)</b><br>
data/fig4/panel_d/nac_o_tilde.dat<br>
data/fig4/panel_d/nac_o_star.dat<br>
data/fig4/panel_d/nac_o_bl.dat<br>
First column; Second column = Net atomic charge (e); Probability<br>
<br>
<b>Distribution function of the NAC Au*, Au\tilde, Au (1st layer)</b><br>
data/fig4/panel_e/nac_au_tilde.dat<br>
data/fig4/panel_e/nac_au_star.dat<br>
data/fig4/panel_e/nac_au_1stlayer.dat<br>
First column; Second column = Net atomic charge (e); Probability<br>
<br>
<b>The charge transfer coordinate of O*</b><br>
data/fig5/panel_d/delta.dat<br>
First column; Second column = time (fs); Reaction coordinate (Angstrom)<br>
<br>
<b>The NAC of the involved AuI and AuII atoms</b><br>
data/fig5/panel_e/auI.dat<br>
data/fig5/panel_e/auII.dat<br>
First column; Second column = time (fs); Net atomic charge (e)<br>
<br>
<b>The NAC of the involved OI-AuI and OII-AuII atoms</b><br>
data/fig5/panel_f/dist_oI-auI.dat<br>
data/fig5/panel_f/dist_oII-auII.dat<br>
First column; Second column = time (fs); Distance (Angstrom)<br>

<br>
<b>Evolution of the instantaneous computational voltages for acidic and alkaline systems</b><br>
data/si/fig1/voltage_naoh.dat<br>
data/si/fig1/voltage_hclo4.dat<br>
First column; Second column = time (ps); Voltage (V)<br>
<br>
<b>Evolution of the instantaneous computational voltage and the corresponding surface charge density</b><br>
data/si/fig2/sigma.dat<br>
First column; Second column = time (ps); Surface charge density (\micro\Coulomb cm^-2)<br>
data/si/fig2/voltage_hclo4.dat<br>
First column; Second column = time (ps); Voltage (V)<br>

<br>
<b>Positions of H3O+ at finite surface charge density conditions corresponding to a computational bias of -3 V</b><br>
data/si/fig3/upper/h3o_pos.dat<br>
data/si/fig3/lower/h3o_pos_1.dat<br>
data/si/fig3/lower/h3o_pos_2.dat<br>
data/si/fig3/lower/h3o_pos_3.dat<br>
data/si/fig3/lower/h3o_pos_4.dat<br>
data/si/fig3/lower/h3o_pos_5.dat<br>
data/si/fig3/lower/h3o_pos_6.dat<br>
data/si/fig3/lower/h3o_pos_7.dat<br>
data/si/fig3/lower/h3o_pos_8.dat<br>
data/si/fig3/lower/h3o_pos_9.dat<br>
First column; Second column = time (ps); H3O+ Position (Angstrom)<br>
<br>
<b>Positions of H3O+ at zero surface charge density (pzc conditions)</b><br>
data/si/fig4/upper/h3o_pos_1.dat<br>
data/si/fig4/upper/h3o_pos_2.dat<br>
data/si/fig4/upper/h3o_pos_3.dat<br>
data/si/fig4/upper/h3o_pos_4.dat<br>
data/si/fig4/upper/h3o_pos_5.dat<br>
data/si/fig4/upper/h3o_pos_6.dat<br>
data/si/fig4/upper/h3o_pos_7.dat<br>
data/si/fig4/upper/h3o_pos_8.dat<br>
data/si/fig4/upper/h3o_pos_9.dat<br>
First column; Second column = time (ps); H3O+ Position (Angstrom)<br>
data/si/fig4/lower/h3o_pos_1.dat<br>
data/si/fig4/lower/h3o_pos_2.dat<br>
data/si/fig4/lower/h3o_pos_3.dat<br>
data/si/fig4/lower/h3o_pos_4.dat<br>
First column; Second column = time (ps); H3O+ Position (Angstrom)<br>
<br>
<b>Probability distributions of the cosine of the angle \theta of OH vectors in the acidic and alkaline aqueous solutions</b><br>
data/si/fig5/panel_a/oh_angle_hclo4_pzc.dat<br>
data/si/fig5/panel_a/oh_angle_hclo4_vm2.dat<br>
data/si/fig5/panel_a/oh_angle_hclo4_vm3.dat<br>
First column; Second column = Angle cos(\theta); Probability<br>
data/si/fig5/panel_b/oh_angle_naoh_pzc.dat<br>
data/si/fig5/panel_b/oh_angle_naoh_v1.dat<br>
First column; Second column = Angle cos(\theta); Probability<br>
<br>
<b>Hydrogen bonding (HB) network statistics</b><br>
data/si/fig6/hb_naoh_v1_if.dat<br>
data/si/fig6/hb_hclo4_vm3_if.dat<br>
data/si/fig6/hb_hclo4_vm2_if.dat<br>
data/si/fig6/hb_hclo4_v0_if.dat<br>
data/si/fig6/hb_naoh_v1_bulk.dat<br>
data/si/fig6/hb_hclo4_vm3_bulk.dat<br>
data/si/fig6/hb_hclo4_vm2_bulk.dat<br>
data/si/fig6/hb_hclo4_v0_bulk.dat<br>
Columns = D2A0; D2A1; D2A2; D1A0; D1A1; D1A2; D0A0; D0A1; D0A2;<br>
<br>
<b>Probability distribution functions of the cosine of the angle \theta between the vector sum of the O-H bonds in H3O+ and the surface normal.</b><br>
data/si/fig7/Hist_h3o_pos_cosTheta_if.npy<br>
This file contains a 2D dataset, which can be plotted by loading the file Hist_h3o_pos_cosTheta_if.npy using Python, either in a terminal or a Jupyter notebook.
In a terminal run the line below<br>
python3 plot.py<br>
or copy the lines below in in a Jupyter notebook, and run the lines.<br>
import numpy as np<br>
import matplotlib.pyplot as pl<br>
<br>
Hist_h3o_pos_cosTheta_if = np.load('Hist_h3o_pos_cosTheta_if.npy')<br>
fig, ax = pl.subplots(1,1, figsize=(3, 3), dpi=200, sharex=False, sharey=False)
ax.imshow(Hist_h3o_pos_cosTheta_if,cmap='Blues', interpolation='bilinear', origin='lower', aspect='auto')<br>
<br>
ax.minorticks_on()<br>
ax.set_ylabel(r'cos($\theta$)', fontsize=8)<br>
ax.set_xlabel(r'$z$ (Angstrom)', fontsize=8)<br>
ax.tick_params(labeltop=False, top=True, right=True, bottom=True, which='both')<br>
ax.minorticks_on() <br>
ax.set_ylabel(r'cos($\theta$)', fontsize=8)<br>
ax.set_xlabel(r'$z$ (Angstrom)', fontsize=8)<br>
pl.show()<br>
<br>
<b>Radial distribution functions of O a (H3O+)/O(Zundel)-O(water) in the Eigen and (c, d) Zundel states and O(water)-O(water) at the IF (interface) and BL (bulk-like) regions</b><br>
data/si/fig8/panel_a/rdf_Ow-Ow-if-0v.dat<br>
data/si/fig8/panel_a/rdf_Ow-Ow-bl-0v.dat<br>
data/si/fig8/panel_a/rdf_Oa-Ow-if-0v.dat<br>
data/si/fig8/panel_a/rdf_Oa-Ow-bl-0v.dat<br>
First column; Second column = Distance r (Angstrom); Radial distribution function g(r)<br>
data/si/fig8/panel_b/rdf_Ow-Ow-if-m3v.dat<br>
data/si/fig8/panel_b/rdf_Ow-Ow-bl-m3v.dat<br>
data/si/fig8/panel_b/rdf_Oa-Ow-if-m3v.dat<br>
data/si/fig8/panel_b/rdf_Oa-Ow-bl-m3v.dat<br>
First column; Second column = Distance r (Angstrom); Radial distribution function g(r)<br>
<br>
<b>Positions of OH- at finite surface charge density corresponding to a finite
bias of 1 V</b><br>
data/si/fig9/upper/oh_pos_1.dat<br>
data/si/fig9/upper/oh_pos_2.dat<br>
First column; Second column = time (fs); Position z (Angstrom)<br>
data/si/fig9/lower/oh_pos_3.dat<br>
data/si/fig9/lower/oh_pos_5.dat<br>
data/si/fig9/lower/oh_pos_6.dat<br>
data/si/fig9/lower/oh_pos_9.dat<br>
data/si/fig9/lower/oh_pos_10.dat<br>
data/si/fig9/lower/oh_pos_11.dat<br>
data/si/fig9/lower/oh_pos_12.dat<br>
data/si/fig9/lower/oh_pos_13.dat<br>
data/si/fig9/lower/oh_pos_14.dat<br>
data/si/fig9/lower/oh_pos_15.dat<br>
First column; Second column = time (fs); Position z (Angstrom)<br>
<br>
<b>Density profiles of all O atoms as well as of the O sites of H3O+ and the net atomic
charge (NAC) of the oxygen and hydrogen atoms of the H2O molecules along the surface normal for the acidic solution</b><br>
data/si/fig10/panel_a/mass_density_h3o_0v.dat<br>
data/si/fig10/panel_a/mass_density_h3o_m3v.dat<br>
data/si/fig10/panel_a/mass_density_O_0v.dat<br>
data/si/fig10/panel_a/mass_density_O_m3v.dat<br>
First column; Second column = Distance z (Angstrom); Density \rho (kg L^-1)<br>
<br>
data/si/fig10/panel_b/Deltaq_hclo4.dat<br>
First column; Second column = Distance z (Angstrom); Excess charge ∆q (e)<br>
<br>
<b>Density profiles of all O atoms as well as of the O sites of OH- and the net atomic
charge (NAC) of the oxygen and hydrogen atoms of the H2O molecules along the surface normal for the acidic solution</b><br>
data/si/fig11/panel_a/mass_density_O_0v.dat<br>
data/si/fig11/panel_a/mass_density_O_1v.dat<br>
data/si/fig11/panel_a/mass_density_oh_0v.dat<br>
data/si/fig11/panel_a/mass_density_oh_1v.dat<br>
First column; Second column = Distance z (Angstrom); Density \rho (kg L^-1)<br>
data/si/fig11/panel_b/Deltaq_naoh.dat<br>
First column; Second column = Distance z (Angstrom); Excess charge ∆q (e)<br>
<br>
<b>Density profile of OH- at zero surface charge density</b><br>
data/si/fig12/mass_density_oh.dat<br>
First column; Second column = Distance z (Angstrom); Density \rho (kg L^-1)<br>
<br>
<b>Mass density profiles of (a) the oxygen and (b) hydrogen sites of the water molecules as well as (c) probability distribution functions of the cosine of the angle \theta of the OH vector of OH- with respect to the surface normal for the alkaline system</b><br>
data/si/fig13/panel_a/naoh_mass_density_O_v0.dat<br>
data/si/fig13/panel_a/naoh_mass_density_O_v0_7.dat<br>
data/si/fig13/panel_a/naoh_mass_density_O_v1_0.dat<br>
First column; Second column = Distance z (Angstrom); Density \rho (kg L^-1)<br>
<br>
data/si/fig13/panel_b/naoh_mass_density_H_v0.dat<br>
data/si/fig13/panel_b/naoh_mass_density_H_v0_7.dat<br>
data/si/fig13/panel_b/naoh_mass_density_H_v1_0.dat<br>
First column; Second column = Distance z (Angstrom); Density \rho (kg L^-1)<br>
<br>
data/si/fig13/panel_c/oh_angle_v0.dat<br>
data/si/fig13/panel_c/oh_angle_v0_7.dat<br>
data/si/fig13/panel_c/oh_angle_v1_0.dat<br>
First column; Second column = Angle cos(\theta); Probability<br>
<br>
<b>Net atomic charges (NAC) of (a,c) oxygen (O) and (b,d) hydrogen (H) atoms
in water molecules depending on their hydrogen bonding state in the HClO4 system at finite (lower panels) and zero surface charge density (upper penels) conditions</b><br>
Panels a, b, c, and d has the same properties for the HClO 4 system (see the SI for further details on the description)<br>
data/si/fig14/panel_{a,b,c,d}/d2a2.dat<br>
data/si/fig14/panel_{a,b,c,d}/d2a1.dat<br>
data/si/fig14/panel_{a,b,c,d}/d1a2.dat<br>
data/si/fig14/panel_{a,b,c,d}/d1a1.dat<br>
First column; Second column = Net atomic charge (e); Probability<br>
<br>
data/si/fig14/panel_{a,b,c,d}/bulk_d2a2.dat<br>
data/si/fig14/panel_{a,b,c,d}/bulk_d2a1.dat<br>
data/si/fig14/panel_{a,b,c,d}/bulk_d1a2.dat<br>
data/si/fig14/panel_{a,b,c,d}/bulk_d1a1.dat<br>
First column = Mean value of that in bulk<br>
<br>
<b>Net atomic charges (NAC) of (a,c) oxygen (O) and (b,d) hydrogen (H) atoms
in water molecules depending on their hydrogen bonding state in the NaOH system at finite (lower panels) and zero surface charge density (upper penels) conditions</b><br>
Panels a, b, c, and d has the same properties for the NaOH system (see the SI for further details on the description)<br>
data/si/fig15/panel_{a,b,c,d}/d2a2.dat<br>
data/si/fig15/panel_{a,b,c,d}/d2a1.dat<br>
data/si/fig15/panel_{a,b,c,d}/d1a2.dat<br>
data/si/fig15/panel_{a,b,c,d}/d1a1.dat<br>
First column; Second column = Net atomic charge (e); Probability<br>
<br>
data/si/fig15/panel_{a,b,c,d}/bulk_d2a2.dat<br>
data/si/fig15/panel_{a,b,c,d}/bulk_d2a1.dat<br>
data/si/fig15/panel_{a,b,c,d}/bulk_d1a2.dat<br>
data/si/fig15/panel_{a,b,c,d}/bulk_d1a1.dat<br>
First column = Mean value of that in bulk<br>
<br>
<b>NAC distributions of O* as a function of Au* (upper panel) and O\tilde as a function Au\tilde at finite surface charge density corresponding to a finite bias of 1 V</b><br>
data/si/fig16/upper/nac_ostar_austar.npy<br>
data/si/fig16/lower/nac_otilde_autilde.npy<br>
This file contains a 2D dataset, which can be plotted by loading the files nac_ostar_austar.npy or nac_ostar_austar.npy using Python, either in a terminal or a Jupyter notebook.<br>
<br>
import numpy as np<br>
import matplotlib.pyplot as pl<br>
<br>
hist_2d_O0_Au0_resting_aver = np.load('nac_ostar_austar.npy')<br>
hist_2d_Otilde_Autilde_resting_aver = np.load('nac_ostar_austar.npy')<br>
<br>
figwidth = 3.487<br>
figheight = figwidth <br>
fig, ax = pl.subplots(2,1, figsize=(figwidth, figheight), gridspec_kw={'hspace':0.3, 'wspace':0.1}, dpi=200, sharex=True, sharey=True) <br>
cmap_2d='Reds'<br>
ax[0].imshow(hist_2d_O0_Au0_resting_aver, interpolation='nearest', origin='lower', extent=[hist_2d_O0_Au0_resting[0][0], hist_2d_O0_Au0_resting[0][-1], hist_2d_O0_Au0_resting[0][0], hist_2d_O0_Au0_resting[0][-1]], cmap=cmap_2d, aspect='auto')<br>
ax[1].imshow(hist_2d_Otilde_Autilde_resting_aver, interpolation='nearest', origin='lower', extent=[hist_2d_O0_Au0_resting[0][0], hist_2d_O0_Au0_resting[0][-1], hist_2d_O0_Au0_resting[0][0], hist_2d_O0_Au0_resting[0][-1]], cmap=cmap_2d, aspect='auto')<br>
for i in range(len(ax)):<br>
 ax[i].minorticks_on()<br>
ax[0].set_ylim(-0.85, -0.5)<br>
ax[1].set_xlim(-0.15,0.2)<br>
ax[1].set_ylim(-0.85, -0.5)<br>
ax[0].set_ylabel(r'NAC O$^{*}$ ($e$)', fontsize=legend_font_size)<br>
ax[1].set_ylabel(r'NAC $\tilde{\textrm{O}}$ ($e$)', fontsize=legend_font_size)<br>
ax[0].set_xlabel(r'NAC Au$^{*}$ ($e$)', fontsize=legend_font_size)<br>
ax[1].set_xlabel(r'NAC $\tilde{\textrm{Au}}$ ($e$)', fontsize=legend_font_size)<br>
pl.show()<br>
description: Expanded related publication citation