Newns-Anderson model for Chemisorption

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Newns-Anderson model for Chemisorption
Bo Hellsing Department of Physics, Göteborg
University, Göteborg, SWEDEN
Atom
Metal
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Newns-Anderson model Hamiltonian
E
Vak
a gt
k gt
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We will apply the Hartree-Fock approximation
(mean filed approximation). The adsorbate Green's
function is obtained which can be used to
calculate e.g. electron charge transfer between
the adsorbate and the substrate
and the adsorbate-substrate binding energy -
chemisorption energy. Crusial quantities are the
adsorbate-substrate interaction Vak and the
coulomb interaction on the adsorbate U. The
retarded Green's function has the elements
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We now derive the equation of motion for the
Green's functions. We start by taking the time
derivative
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Heisenberg
We thus get
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Hand-in problem I
We thus get