Abstract
Inelastic x-ray scattering measurements on liquid Bi were carried out. Prominent acoustic mode excitations were observed in the dynamic structure factor to beyond , which resolves previously conflicting results as to their presence beyond . We find the dispersion curve of the excitation energy with momentum transfer is nearly flat from 7 to consistent with ab initio calculations of liquid Bi [J. Souto et al., Phys. Rev. B 81, 134201 (2010)]. Our ab initio and classical molecular dynamics simulations suggest that a long-range force is needed to reproduce the flatness of the dispersion curve, and the long-range force is correlated with a local structure consisting of shorter and longer bonds in the liquid.
- Received 14 September 2014
- Revised 5 June 2015
DOI:https://doi.org/10.1103/PhysRevB.92.054206
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