Raman spectra from ab initio molecular dynamics and its application to liquid S-methyloxirane.

We describe the calculation of Raman spectra for periodic systems via ab initio molecular dynamics (AIMD) utilizing the Gaussian and plane wave method in the program package CP2K. The electric-dipole-electric-dipole polarizability tensor has been implemented for an arbitrary shape of the simulation cell. In addition, a computationally efficient approach for its decomposition into local contributions is presented. As an example for the application of computational Raman spectroscopy to liquids, the Raman spectra of S-methyloxirane in the liquid phase have been calculated together with Raman spectra obtained from static calculations employing the double-harmonic approximation. The comparison to experimental data illustrates that a very good agreement between experiment and simulated spectra can be obtained employing AIMD, which takes into account anharmonicities and dynamical effects at ambient conditions.