Data from: Ab initio insights into the hydrated dielectron: Structure and recombination dynamics
Data files
May 06, 2026 version files 17.62 MB
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density_recom_vid.zip
16.94 MB
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README.md
3.04 KB
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traj_inp_recomb.zip
40.86 KB
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woc_tunn_vid.zip
639.17 KB
Abstract
Despite extensive research on the behavior and properties of single hydrated electrons, relatively little is known about self-recombination of two hydrated electrons to form a hydrated dielectron. Hydrated dielectrons are hypothesized to be important in the radiation chemistry of water, particularly as an intermediate in the dielectron hydrogen evolution reaction (DEHE) that produces molecular hydrogen: e - hyd + e - hyd + 2H2O → 2OH - + H2. In this work, we investigate the solvation structures and recombination dynamics of both singlet and triplet hydrated electron pairs in bulk water using DFT-based ab initio molecular dynamics simulations. Our findings reveal that the recombination reaction leading to dielectron formation occurs exclusively from the singlet state, with the dielectron occupying a slightly larger cavity than the single electron. The potential of mean force for open-shell singlet electron pairs has a local minimum at a distance corresponding to a metastable state in which two electron cavities are separated by a single bridging water molecule. From this state, recombination to form dielectrons occurs by two distinct mechanisms: diffusive recombination and direct tunneling. These pathways have an approximately 1:1 branching ratio, a balance set by the symmetry of the local solvation environment. Diffusion occurs when both electrons experience similar, coupled solvation environments, while tunneling is triggered when asymmetric solvation destabilizes one electron, which then tunnels into the more stable cavity of the electron pair in a manner mediated by the bridging water molecule.
Dataset DOI: 10.5061/dryad.gmsbcc32c
Description of the data and file structure
Here we share videos showing recombination of two hydrated electrons (singlet state) which are initially separated by a bridging water using Wannier orbital centers (WOC) and maximally-localized Wannier Function (MLWF) densities. We also share an input file used to generate our trajectories as well as representative coordinates of select configurations from a previous run with two separate hydrated electrons in the triplet state. The MLWF densities were generated using Multiwfn (http://sobereva.com/multiwfn/index.html) and the videos were generated using VMD (https://www.ks.uiuc.edu/Research/vmd/). Our trajectories were performed using the CP2K package (https://www.cp2k.org/) so the input file shared here is compatible with CP2K. We found that recombination can occur either by diffusion or by tunneling. The files representing trajectories are referenced as "t" for trajectory followed by the trajectory number. Tunneling trajectories are labeled as t3, t8, t10, t11, t15, t16, t19 and for diffusion, t1, t2, t4, t9, t12, t14.
Files and variables
Technical Note: The included .mp4 video files were generated using VMD movie maker (VideoMach.exe). Unfortunately, QuickTime may not display the videos. For the best viewing experience, we recommend using VLC Media Player or Windows Media Player.
File: density_recom_vid.zip
Description: Videos showing MLWF densities of electron pairs colocalizing. The densities are represented as blue and green wire mesh surfaces. Nearby waters are also visible in the video with the bridging water purposely having a yellow oxygen, as opposed to red, to better distinguish it from the rest of the waters. The files are listed as t#_den where den is short for density.
File: woc_tunn_vid.zip
Description: Videos showing trajectories with tunneling ("tunn" in the file names) recombination where electrons are represented by their WOC and where the bridging water is the only water in the videos. This along, with the density videos, and the publication, we show that one hydrated electron tunnels through the bridging water and into the cavity of the pair electron.
File: traj_inp_recomb.zip
Description: We have a sample input file "t1_electron_fully_periodic.inp" which is representative of the first trajectory along with the coordinates of the configuration used "t1_triplet_config.cp2k". Additionally, we have coordinates of configurations used to create the other representative trajectories "t#_triplet_config.cp2k". If one would like to reproduce this work, using any .cp2k file, they would just need to modify the input line "@include 't1_triplet_config.cp2k'" to the desired .cp2k file.