The method of increments applied to binding on surfaces
Beate Paulus
Max-Planck-Institut Dresden
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Since the last decade a great success was made in calculating ground-state properties of
insulators and semiconductors bulk with ab initio quantum-chemical methods.
The coupled-cluster approach is used to correct the Hartree-Fock crystal results
for correlations and to systematically improve
the ground-state wavefunction and ground-state properties of the solid.
The correlation calculations based upon the method of increments[1], which is an expansion of
the total correlation energy in terms of localized one-center, two-center, and higher
contributions.
Here we want to apply the method of increments to adorption energies of molecules on surfaces.
Especially for the dispersive adsorption
energies an explicitely correlated method
is necessary to describe accurately the van der Waals interaction. DFT approached often fail with
the respect to dispersion forces. The advantage of the incremental scheme is, that for not-chemical
bound adsorbats, the binding energy can be directly calculated with the two-body terms between
the molecule and the atoms of the surface. As first examples we tested the binding of CO on
the (110) surface of CeO2 and binding of H2S on a graphene sheet.
[1] B. Paulus, Phys. Rep. 428, 1 (2006).