Electronic structure effects from hydrogen bonding in the liquid phase and in chemisorption: an integrated theory and experimental effort
2001 (English)In: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 8, 136-140 p.Article in journal (Refereed) Published
A closely integrated theoretical and experimental effort to understand chemical bonding using X-ray spectroscopic probes is presented. Theoretical techniques to simulate XAS (X-ray absorption spectroscopy), XES (X-ray emission spectroscopy), RIXS (resonant inelastic X-ray scattering) and XPS (X-ray photoelectron spectroscopy) spectra have been developed and implemented within a density functional theory (DFT) framework. In combination with new experimental techniques, such as high-resolution XAS on liquid water under ambient conditions and XES on complicated surface adsorbates, new insight into e.g. hydrogen-bonded systems is obtained. For the (3 x 2) overlayer structure of glycine/Cu(110), earlier work has been extended to include adsorbate-adsorbate interactions. Structures are optimized for large cluster models and for periodic boundary conditions. It is found that specific features in the spectra arise from hydrogen-bonding interactions, which thus have important effects at the molecular-orbital level. XAS on liquid water shows a pronounced pre-edge feature with significant intensity, while the spectrum of ice shows only little intensity in this region. Theoretical spectrum calculations, based on instantaneous structures obtained from molecular-dynamics (MD) simulations, show that the pre-edge feature in the liquid is caused by water molecules with unsaturated hydrogen bonding. Some aspects of the theoretical simulations will be briefly discussed.
Place, publisher, year, edition, pages
2001. Vol. 8, 136-140 p.
hydrogen bonding, density functional theory (DFT), glycine/Cu(110), liquid XAS, exchange-energy, ab-initio, glycine, cu(110), adsorption, approximation, spectra, water
IdentifiersURN: urn:nbn:se:kth:diva-20416ISI: 000167298100019OAI: oai:DiVA.org:kth-20416DiVA: diva2:339111
QC 201005252010-08-102010-08-10Bibliographically approved