First-principles study of second-order nonlinear susceptibility of water adsorption layer on Pt(111) surface

Basic understanding of metal/water interface is essential for electrochemical devices, and water adsorptions on metal surface are one of the simplified systems for investigating the interface property. Recently, second-order nonlinear susceptibilities χ⁽²⁾ of H₂O layers on Pt(111) (ω_IR ∼ 3000 cm^-1) was obtained by sum-frequency generation spectroscopy, and the observed spectra revealed the structure of hydrogen-bond network of water layers. [1] The aim of this study is to establish calculation of χ⁽²⁾ by first-principles method and to obtain χ⁽²⁾ spectra of Pt(111)/H₂O layers. By applying the density functional perturbation theory (DFPT) [2] and effective screening medium (ESM) method [3], we have succeeded in obtaining the χ⁽²⁾ spectra of Pt(111)/H₂O layers. In the presentation, we will explain the detailed calculations, and discuss the comparison between theoretical calculations and the experiment.

[1] Nat. Phys. 12, 1063 (2016). [2] Rev. Mod. Phys. 73, 515 (2001). [3] Phys. Rev. B 73, 115407 (2006).