Abstract: J. Chem. Phys. 111 (1999) 4704-4713
M. Staufer, U. Birkenheuer, T. Belling, F. Nörtemann,
N. Rösch, M. Stichler, C. Keller, W. Wurth, D. Menzel,
L. G. M. Pettersson, A. Föhlisch, and A. Nilsson
Interpretation of X-Ray Emission Spectra: NO Adsorbed on Ru(001)
J. Chem. Phys. 111 (1999) 4704-4713.
[Sep. 8, 1999]
A density functional investigation of the x-ray emission spectrum of NO adsorbed on Ru(001) has been carried out using model cluster calculations. The dipole matrix elements governing the emission probability were evaluated in the frozen ground-state approximation. The resulting simulated spectra exhibit all characteristic features of the experimental data. A detailed analysis of the electronic structure of the model clusters permits a complete rationalization of all observed trends. Furthermore, a picture of the surface chemical bond results in which the classical Blyholder frontier orbital model is extended to a three-orbital description for both the pi and sigma interactions. Comparison of different adsorption sites reveals that threefold coordinated NO features a stronger orbital interaction with the substrate than NO adsorbed in an on-top position.