Accuracy and limitations of the bond polarizability model in modeling of Raman scattering from molecular dynamics simulations

Atanu Paul; Maya Rubenstein; Anthony Ruffino; Stefan Masiuk; Jonathan E Spanier; Ilya Grinberg

doi:10.1063/5.0217227

Accuracy and limitations of the bond polarizability model in modeling of Raman scattering from molecular dynamics simulations

J Chem Phys. 2024 Aug 14;161(6):064305. doi: 10.1063/5.0217227.

Authors

Atanu Paul¹, Maya Rubenstein¹, Anthony Ruffino², Stefan Masiuk³, Jonathan E Spanier^{2

3}, Ilya Grinberg¹

Affiliations

¹ Department of Chemistry, Bar-Ilan University, Ramat Gan 5290002, Israel.
² Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104, USA.
³ Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, Pennsylvania 19104, USA.

PMID: 39132793
DOI: 10.1063/5.0217227

Abstract

Calculation of Raman scattering from molecular dynamics (MD) simulations requires accurate modeling of the evolution of the electronic polarizability of the system along its MD trajectory. For large systems, this necessitates the use of atomistic models to represent the dependence of electronic polarizability on atomic coordinates. The bond polarizability model (BPM) is the simplest such model and has been used for modeling the Raman spectra of molecular systems but has not been applied to solid-state systems. Here, we systematically investigate the accuracy and limitations of the BPM parameterized from the density functional theory results for a series of simple molecules, such as CO2, SO2, H2S, H2O, NH3, and CH4; the more complex CH2O, CH3OH, CH3CH2OH, and thiophene molecules; and the BaTiO3 and CsPbBr3 perovskite solids. We find that BPM can reliably reproduce the overall features of the Raman spectra, such as shifts of peak positions. However, with the exception of highly symmetric systems, the assumption of non-interacting bonds limits the quantitative accuracy of the BPM; this assumption also leads to qualitatively inaccurate polarizability evolution and Raman spectra for systems where large deviations from the ground state structure are present.