DFT study on Raman frequencies of molten lead (II) chloride

The study concerns ab inito calculations of the essential Raman frequencies of molten lead (II) chloride near the melting point. Modelling of topologically disordered lead (II) chloride was carried out within the framework of the density functional theory using the Perdew–Burke-Ernzerhof (PBE) functional and optimised basis sets. Calculations were performed for a cluster containing 24 formula units. The optimum geometry of the cluster was determined and the local structure parameters were found. Nano-size effect leads to the picture of damped oscillations on radial atomic density distributions typical of molten salts. Distorted octahedra of PbCl₆ were detected inside the cluster. Ab initio calculation of the Raman spectrum of the octahedral complexes inside the cluster structure was implemented. It was shown that the spectrum has a peak at 192 cm^?1, which agrees well with the experimental Raman spectra of lead (II) chloride melt near the melting point.