A Polarizable QM/MM Explicit Solvent Model for Computational Electrochemistry in Water
We present a quantum mechanical/molecular mechanical (QM/MM) explicit solvent model for the computation of standard reduction potentials E[subscript 0]. The QM/MM model uses density functional theory (DFT) to model the solute and a polarizable molecular mechanics (MM) force field to describe the sol...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Chemical Society (ACS)
2013
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| Online Access: | http://hdl.handle.net/1721.1/76274 https://orcid.org/0000-0001-7111-0176 |
| Summary: | We present a quantum mechanical/molecular mechanical (QM/MM) explicit solvent model for the computation of standard reduction potentials E[subscript 0]. The QM/MM model uses density functional theory (DFT) to model the solute and a polarizable molecular mechanics (MM) force field to describe the solvent. The linear response approximation is applied to estimate E[subscript 0] from the thermally averaged electron attachment/detachment energies computed in the oxidized and reduced states. Using the QM/MM model, we calculated one-electron E[subscript 0] values for several aqueous transition-metal complexes and found substantially improved agreement with experiment compared to values obtained from implicit solvent models. A detailed breakdown of the physical effects in the QM/MM model indicates that hydrogen-bonding effects are mainly responsible for the differences in computed values of E[subscript 0] between the QM/MM and implicit models. Our results highlight the importance of including solute–solvent hydrogen-bonding effects in the theoretical modeling of redox processes. |
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