Orientation of aromatic hydrocarbons on metal surfaces as determined by NEXAFS

Yannoulis, P.; Dudde, R.; Frank, K. H.; Koch, E. E.

doi:10.1016/0167-2584(87)90487-7

Cited by 2 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted that previous investigations of coronene films on Ag(111) report, in addition to an azimuthal rotation, an out-of-plane tilt of the molecules as deduced from STM and force-field calculations 12 as well as by near-edge X-ray absorption fine structure (NEXAFS) measurements. 33 In the case of the NEXAFS measurements, however, 2 to 3 ML thick films had been prepared, where a tilt of the molecules in the second and higher layers might be responsible for the overall molecular tilt concluded. 33 In contrast to the NEXAFS measurement on Ag(111), carbon K-edge XAFS measured on coronene monolayers on Au(111) confirmed flat-lying molecules.…”

Section: Resultsmentioning

confidence: 99%

“… 33 In the case of the NEXAFS measurements, however, 2 to 3 ML thick films had been prepared, where a tilt of the molecules in the second and higher layers might be responsible for the overall molecular tilt concluded. 33 In contrast to the NEXAFS measurement on Ag(111), carbon K-edge XAFS measured on coronene monolayers on Au(111) confirmed flat-lying molecules. 31 We emphasize that our DFT structural optimizations do not indicate an out-of-plane tilt of the molecules on either the Ag(111) or on the Au(111) surface.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Film and Substrate Structure on Photoelectron Momentum Maps of Coronene Thin Films on Ag(111)

et al. 2017

View full text Add to dashboard Cite

Angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) was measured for one-monolayer coronene films deposited on Ag(111). The (kx,ky)-dependent photoelectron momentum maps (PMMs), which were extracted from the ARUPS data by cuts at fixed binding energies, show finely structured patterns for the highest and the second-highest occupied molecular orbitals. While the substructure of the PMM main features is related to the 4 × 4 commensurate film structure, various features with three-fold symmetry imply an additional influence of the substrate. PMM simulations on the basis of both free-standing coronene assemblies and coronene monolayers on the Ag(111) substrate confirm a sizable molecule–molecule interaction because no substructure was observed for PMM simulations using free coronene molecules.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Influence of Film and Substrate Structure on Photoelectron Momentum Maps of Coronene Thin Films on Ag(111)

et al. 2017

View full text Add to dashboard Cite

show abstract

“…1 The ability of XAS to simultaneously characterize both the electronic and geometrical structure of chemical systems has made it indispensable in the fields of catalysis and photophysics. [2][3][4][5][6] However, despite the capability of XAS to obtain a wealth of chemically relevant information, the complexity of experimentally obtained XAS spectra often requires a theoretical supplement to obtain a meaningful interpretation of the query phenomenon. 7,8 Thus, the ability to properly describe the high-energy electronic excitations of molecular systems theoretically is critical in modern electronic structure theory.…”

Section: Introductionmentioning

confidence: 99%

Model Order Reduction Algorithm for Estimating the Absorption Spectrum

Beeumen

Williams‐Young

Kasper

et al. 2017

J. Chem. Theory Comput.

View full text Add to dashboard Cite

The ab initio description of the spectral interior of the absorption spectrum poses both a theoretical and computational challenge for modern electronic structure theory. Due to the often spectrally dense character of this domain in the quantum propagator's eigenspectrum for medium-to-large sized systems, traditional approaches based on the partial diagonalization of the propagator often encounter oscillatory and stagnating convergence. Electronic structure methods which solve the molecular response problem through the solution of spectrally shifted linear systems, such as the complex polarization propagator, offer an alternative approach which is agnostic to the underlying spectral density or domain location. This generality comes at a seemingly high computational cost associated with solving a large linear system for each spectral shift in some discretization of the spectral domain of interest. In this work, we present a novel, adaptive solution to this high computational overhead based on model order reduction techniques via interpolation. Model order reduction reduces the computational complexity of mathematical models and is ubiquitous in the simulation of dynamical systems and control theory. The efficiency and effectiveness of the proposed algorithm in the ab initio prediction of X-ray absorption spectra is demonstrated using a test set of challenging water clusters which are spectrally dense in the neighborhood of the oxygen K-edge. On the basis of a single, user defined tolerance we automatically determine the order of the reduced models and approximate the absorption spectrum up to the given tolerance. We also illustrate that, for the systems studied, the automatically determined model order increases logarithmically with the problem dimension, compared to a linear increase of the number of eigenvalues within the energy window. Furthermore, we observed that the computational cost of the proposed algorithm only scales quadratically with respect to the problem dimension.

show abstract

Orientation of aromatic hydrocarbons on metal surfaces as determined by NEXAFS

Cited by 2 publications

References 0 publications

Influence of Film and Substrate Structure on Photoelectron Momentum Maps of Coronene Thin Films on Ag(111)

Influence of Film and Substrate Structure on Photoelectron Momentum Maps of Coronene Thin Films on Ag(111)

Model Order Reduction Algorithm for Estimating the Absorption Spectrum

Contact Info

Product

Resources

About