On the core hole screening mechanism in adsorbates in the absence of low lying π acceptor orbitals

摘要: Abstract To investigate the effects of absence low lying π* acceptor orbitals on ligand core hole spectra molecules adsorbed metal surfaces, we considered nitrogen 1s spectrum NH3/Ni system. We have performed ab initio 1h1p/2h1p and 2h2p/3h2p configuration interaction (CI) calculations NiNH3 molecule, using an extended basis set. several initial states. Despite great variety final states considered, present model suggests presence a satellite significant intensity within couple eV from main line (both which can be actually made closely spaced components generated by additional many-body effects). The active mechanism is relaxation Ni 4sp electron in essentially d94s(p) towards NH3 Rydberg antibonding virtual orbitals. This with previous finding Hermann Bagus. lack orbital forbids π charge transfer (CT) associated dπ—π* backbonding, essential to s—dσ promotion mechanism. Furthermore this CT screening forces pure σ sp orbitals, generating appearance σ—σ* satellites, albeit different origin.