Effect of the STM Tip Surface States on Electronic-Vibrational Excitations of H2O Molecules Adsorbed on Gold Nanoparticles

In this work we consider inelastic electron tunneling transition through the molecule in the vacuum gap in experiments with scanning tunneling microscope (STM). It was demonstrated that the enhanced density of electronic surface states (DOS) of the STM tip can lead to peak formation in the STM tunneling current spectra. A method was proposed to simulate the surface DOS of the STM tip. Based on the STM-obtained spectra of electron-vibrational excitations of the H₂O molecule, the parameters of surface DOS peak for tungsten tip were calculated. It was demonstrated that surface states and surface resonances with the symmetry \(d_{z}^{2}\) of the W(100) surface provides the formation of tunneling current peak in STM experiments.