"On-The-Fly" Calculation of the Vibrational Sum-Frequency Generation Spectrum at the Air-Water Interface

Deepak Ojha; Thomas D Kühne

doi:10.3390/molecules25173939

"On-The-Fly" Calculation of the Vibrational Sum-Frequency Generation Spectrum at the Air-Water Interface

Molecules. 2020 Aug 28;25(17):3939. doi: 10.3390/molecules25173939.

Authors

Deepak Ojha¹, Thomas D Kühne^{1

2}

Affiliations

¹ Dynamics of Condensed Matter and Center for Sustainable Systems Design, Chair of Theoretical Chemistry, Department of Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, Germany.
² Paderborn Center for Parallel Computing and Institute for Lightweight Design, Paderborn University, Warburger Str. 100, D-33098 Paderborn, Germany.

Abstract

In the present work, we provide an electronic structure based method for the "on-the-fly" determination of vibrational sum frequency generation (v-SFG) spectra. The predictive power of this scheme is demonstrated at the air-water interface. While the instantaneous fluctuations in dipole moment are obtained using the maximally localized Wannier functions, the fluctuations in polarizability are approximated to be proportional to the second moment of Wannier functions. The spectrum henceforth obtained captures the signatures of hydrogen bond stretching, bending, as well as low-frequency librational modes.

Keywords: AIMD; air-water interface; on-the-fly; vSFG.

MeSH terms

Air / analysis*
Algorithms
Models, Theoretical*
Spectrum Analysis*
Surface Properties
Water / chemistry*

Substances

Water

Grants and funding

716142/H2020 European Research Council