Abstract (eng)
We study vibrational spectra of water confined inside various types of carbon nanotubes. The water molecules form different kinds of ordered structures depending on temperature, density and the diameter of the nanopore. We simulate the system using molecular dynamics methods and apply perturbation theory to calculate vibrational frequencies. We study the motional narrowing effect in these systems by taking into account the vibrational lifetime of OH excitations and the dipole-dipole time correlation of the OH stretch. The resulting spectra reveal the distinct order in the different tubes, and suggest that these structures can also be tested experimentally through infrared spectroscopy. Furthermore, we compare the strong correlation between the E-field at the hydrogen and the vibrational frequency in these systems to the correlation in bulk.