Examinando por Materia "Molecules"

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    Ítem
    Structural characterization of the (MeSH) 4 potential energy surface
    (Springer-Verlag, 2013-01-10) Guerra Tamayo, Doris Lucía; Restrepo Cossio, Albeiro Alonso; Gómez Maya, Sara Luz; David Caro, Jorge León; Universidad EAFIT. Departamento de Ciencias Básicas; Jorge León David Caro (jdavidca@eafit.edu.co); Electromagnetismo Aplicado (Gema)
    A random walk on the PES for (MeSH)4 clusters produced 50 structural isomers held together by hydrogenbonding networks according to calculations performed at the B3LYP/6–311++G** and MP2/6–311++G** levels -- The geometric motifs observed are somewhat similar to those encountered for the methanol tetramer, but the interactions responsible for cluster stabilization are quite different in origin -- Cluster stabilization is not related to the number of hydrogen bonds -- Two distinct, well-defined types of hydrogen bonds scattered over a wide range of distances are predicted
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    Ítem
    Substantial improvement of electrocatalytic predictions by systematic assessment of solvent effects on adsorption energies
    (Elsevier B.V., 2020-01-01) Rendón-Calle A.; Builes S.; Calle-Vallejo F.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    Electrocatalytic activities are largely determined by the interplay of adsorbates with substrates and solvents. Although capturing the interactions of those three components is usually arduous, here we provide a simple micro-solvation method to evaluate them in aqueous media. The method helps determine: (a) the number of water molecules making hydrogen bonds with the adsorbates, and (b) the energetic stabilization of the adsorbates by those hydrogen bonds. To evaluate the usefulness of the method, we consider CO2 reduction to CO, CH4, and CH3OH on Cu, Ag, Au, and Zn. Applying the calculated solvation corrections, we find good agreement with experiments in the predicted pathways and onset potentials, with an average error of only 0.07 V. Conversely, models with ad hoc or implicit solvation corrections predict unlikely pathways and onset potentials with considerably larger errors. These results indicate that accurate methods to assess solvent-adsorbate interactions contribute to improve computational electrocatalysis models. © 2020 Elsevier B.V.