By means of classical density-functional theory the authors study the density distribution of mobile Ag+ ions in alpha -AgI-type superionic conductors taking into account the thermal fluctuations in the anion host lattice. Their model is based on an expansion of the 'external' potential v(r) acting on the cation-component up to second order in the displacements of anions, the latter being regarded as Einstein oscillators. Calculated density profiles are compared with molecular-dynamics simulations. For alpha -AgI the agreement is almost quantitative. In the case of beta -Ag2S the inclusion of anion vibrations leads to significant corrections in the temperature-dependent profiles.
Roman, H., Dieterich, W. (1990). Density-functional approach for superionic conductors: Effects of host-lattice deformations. JOURNAL OF PHYSICS. CONDENSED MATTER, 2(44), 8813-8825 [10.1088/0953-8984/2/44/010].
Density-functional approach for superionic conductors: Effects of host-lattice deformations
Roman H. E.;
1990
Abstract
By means of classical density-functional theory the authors study the density distribution of mobile Ag+ ions in alpha -AgI-type superionic conductors taking into account the thermal fluctuations in the anion host lattice. Their model is based on an expansion of the 'external' potential v(r) acting on the cation-component up to second order in the displacements of anions, the latter being regarded as Einstein oscillators. Calculated density profiles are compared with molecular-dynamics simulations. For alpha -AgI the agreement is almost quantitative. In the case of beta -Ag2S the inclusion of anion vibrations leads to significant corrections in the temperature-dependent profiles.
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