2026/07/27 by Xintian Wang, Andrew L. Goodwin, Theodosios Famprikis
#cond-mat.dis-nn #physics.chem-ph
We characterise the interplay between cation-translational and anion-rotational dynamics on the model system \rm α-Li2SO4 through virtual isotopic substitution molecular dynamics (VISMD) simulations. We independently control in turn the lithium translational- and sufate rotational- diffusivity by varying the masses of lithium and oxygen, respectively, showing that both diffusivities exhibit power-law relationships with the masses of each individual component. Changing either diffusivity produces an effect on the other; i.e. there exists a bidirectional coupling between anion and cation diffusive dynamics. From our variable-temperature/variable-mass dataset we demonstrate that the apparent activation energy for lithium diffusion depends strongly on the isotope mass, decreasing with accelerated sulfate dynamics; an observation which provides clear evidence of mode-coupling between cation and anion dynamics.