Local structure and vibrational properties of molten lead halides PbX2 (X=Cl, Br, I) from ab initio molecular dynamics

Publication date: Available online 29 March 2019Source: Computational and Theoretical ChemistryAuthor(s): Dmitry Zakiryanov, Nikolai TkachevAbstractAb initio molecular dynamics (AIMD) was applied to calculate the local structure and dynamics parameters of molten lead halides PbX2 (X = Cl, Br, I). The thoroughness of our approach is substantiated by the variation of both cell size and temperature. The total duration of AIMD runs amounted to 600 ps. It was found that molten lead chlorides exhibit weak binding of the local structure. The latter was analyzed by means of radial distribution functions for each pair of salt constituents. The radial distribution functions exhibit pronounced liquid-like damped oscillations and weakly depend on the cell size. In terms of vibrational properties, we highlight the frequencies of 125 cm-1 and 80 cm-1 which relate to the Pb-Br and Pb-I vibrations respectively, both of a short lifetime. These results are additionally supported by the calculated self-diffusion coefficients which concur closely with experimental values.Graphical abstract
Source: Computational and Theoretical Chemistry - Category: Chemistry Source Type: research