Quantum Mechanics/Molecular Mechanics Modeling of Photoelectron Spectra: The Carbon 1s Core-Electron Binding Energies of Ethanol-Water Solutions
2014 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 118, no 46, 13217-13225 p.Article in journal (Refereed) Published
Using ethanolwater solutions as illustration, we demonstrate the capability of the hybrid quantum mechanics/molecular mechanics (QM/MM) paradigm to simulate core photoelectron spectroscopy: the binding energies and the chemical shifts. An integrated approach with QM/MM binding energy calculations coupled to preceding molecular dynamics sampling is adopted to generate binding energies averaged over the solutesolvent configurations available at a particular temperature and pressure and thus allowing for a statistical assessment with confidence levels for the final binding energies. The results are analyzed in terms of the contributions in the molecular mechanics modelelectrostatic, polarization, and van der Waalswith atom or bond granulation of the corresponding MM charge and polarizability force-fields. The role of extramolecular charge transfer screening of the core-hole and explicit hydrogen bonding is studied by extending the QM core to cover the first solvation shell. The results are compared to those obtained from pure electrostatic and polarizable continuum models. Particularly, the dependence of the carbon 1s binding energies with respect to the ethanol concentration is studied. Our results indicate that QM/MM can be used as an all-encompassing model to study photoelectron binding energies and chemical shifts in solvent environments.
Place, publisher, year, edition, pages
2014. Vol. 118, no 46, 13217-13225 p.
Theoretical Chemistry Physical Sciences
IdentifiersURN: urn:nbn:se:kth:diva-158401DOI: 10.1021/jp506410wISI: 000345468600021ScopusID: 2-s2.0-84912530091OAI: oai:DiVA.org:kth-158401DiVA: diva2:778135
QC 201501092015-01-092015-01-072015-01-09Bibliographically approved