Molecular Dynamics Simulation of the Raman Spectra of Supercritical Carbon Dioxide

Abstract

An approach to simulating the Raman spectra of supercritical carbon dioxide was demonstrated. The approach is based on the Fourier analysis of the autocorrelation function of the dipole moment calculated by molecular dynamics. Based on these data, the Raman spectra of carbon dioxide were calculated along the isotherm at 310 K in the pressure range of 0.1–15 MPa. It was determined that, in the Widom delta, the spectral lines are broadened and the pressure dependences of the Raman shifts have extrema. The results obtained agree well with the known experimental data and indicate a significant effect of cluster formation on the macroscopic properties of carbon dioxide in the vicinity of the critical point.