Journal article
Applications of polarizable continuum models to determine accurate solution-phase thermochemical values across a broad range of cation charge - the case of U(III-VI)
Journal of chemical theory and computation, Vol.11(1), pp.55-63
01/13/2015
Handle:
https://hdl.handle.net/2376/108435
PMID: 26574203
Abstract
Contributing factors to the solution-phase correction to the free energy of the molecular clusters U(H2O)n(3+/4+) and UO2(H2O)m(1+/2+) (n = 8, 9, 30, 41, 77; m = 4, 5, 30, 41, 77) have been examined as a function of cavity type in the integrated-equation-formalism-protocol (IEF) and SMD polarizable continuum models (PCMs). It is observed that the free energy correction, Gcorr, does not smoothly converge to zero as the number of explicitly solvating water molecules approaches the bulk limit, and the convergence behavior varies significantly with cavity and model. The rates of convergence of the gas-phase hydration energy, ΔGhyd, wherein the bare metal ion is inserted into a molecular water cluster and ΔGcorr for the reaction exhibit wide variations as a function of ion charge, cavity, and model. This is the likely source of previously reported discrepancies in predicted free energies of solvation for metal ions when using different PCM cavities and/or models. The cancellation of errors in ΔGhyd and ΔGcorr is optimal for clusters consisting of only a second solvation shell of explicit water molecules (n = m = 30). The UFF cavity within IEF, in particular, exhibits the most consistent cancellation of errors when using a molecular cluster consisting of a second shell of solvating water for all oxidation states of uranium, leading to accurate free energies of solvation ΔGsolv for these species.
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Details
- Title
- Applications of polarizable continuum models to determine accurate solution-phase thermochemical values across a broad range of cation charge - the case of U(III-VI)
- Creators
- Payal Parmar - Department of Chemistry and the Materials Science and Engineering Program, Washington State University , Pullman, Washington 99164, United StatesAlex Samuels - Department of Chemistry and the Materials Science and Engineering Program, Washington State University , Pullman, Washington 99164, United StatesAurora E Clark - Department of Chemistry and the Materials Science and Engineering Program, Washington State University , Pullman, Washington 99164, United States
- Publication Details
- Journal of chemical theory and computation, Vol.11(1), pp.55-63
- Academic Unit
- Chemistry, Department of
- Publisher
- United States
- Identifiers
- 99900547002901842
- Language
- English
- Resource Type
- Journal article