ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
In order to study the effect of the potential well on the single ion dynamics and the charge transport in molten LiNO3, a molecular dynamics simulation, which included all degrees of freedom of vibrating nitrate ions, was carried out. Simple Coulomb pair potential with Born-type repulsion was adopted as a standard, and a potential well of varying depth between Li+ and O of NO−3 was added to the standard potential. As the well depth increased, both the translational and orientational diffusion were found to slow down, leading to solid like dynamics. The potential dependence of the ionic dynamics was studied from the translational, orientational, and current correlation functions. Results of the simulation were compared with the experimental diffusion constants, static conductivity, and rotational behavior revealed by Raman spectroscopy. Using the relation between the infrared absorption spectrum and the autocorrelation function of the dipole moment (or the current) of the system, we carried out the first simulation of translational band shapes in an ionic melt, and demonstrated how the absorption spectrum was related to the velocity correlation functions of cations and anions. The infrared and Raman spectroscopy were found to give sensitive criteria for finding a good potential of an ionic liquid. The lifetime of local structures surrounding nitrate ions, which were characterized by the coordination number, was found to increase remarkably as the well depth increased. The coupling between the environmental structure and the translational and rotational behavior of a nitrate ion was examined through selectively sampled correlation functions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.458508
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