Answers are grounded in this paper and cite their sources.
The anharmonic lattice dynamics of (Sr∕Ba)₈Ga₁₆₊ₓGe_30-x type-I clathrates are studied using first-principles calculations. The guest atoms in the large cages are found to lie in strongly anharmonic potentials, resulting in off-center (disordered) equilibrium positions for the Sr rattler. The lowest energy modes for Sr form a four level system with a tunneling splitting of only 0.040.3em0exmeV. The thermodynamical properties and the inelastic neutron scattering spectra of the anharmonic rattlers are investigated.
No takes yet. Share an insight, caveat, or question.
Madsen et al. (2005) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: