Molecular dynamics study of the spectroscopic properties of liquid benzene

A molecular dynamics (MD) simulation, which includes all degrees of freedom of atomic motion, has been performed to investigate several spectroscopic properties such as infrared and Raman spectra, permittivity, and refractive index of liquid benzene. Infrared and Raman spectra of liquid benzene were measured at room temperature, and these experimental results were compared with our MD simulated spectra. The simulated infrared spectra reproduced the four fundamental v 11, v 18, v 19, and v 20 bands, and the simulated Raman spectra reproduced the seven fundamental v 1, v 2, v 6, v 7 v 8, v 9, and v 10 bands as expected from the selection rule. These simulated spectra were in good agreement with the observed ones in the frequency and relative intensity of fundamental vibrations of benzene. The v 16 and v 4 bands appeared in the simulated Raman spectra. These bands are exceptions to the selection rule, and these facts indicate that the breakdown of the symmetry of D6h of a benzene molecule occurs in a liquid state. The simulated permittivity, and refractive index were also in good agreement with other experimental values.