title: Excitations of lithium ammonia complexes studied by inelastic x-ray scattering.
abstract: We have carried out high-resolution inelastic x-ray scattering measurements of the excitations of lithium dissolved in ammonia. The incident x-ray energy was 21.6 keV and the resolution was about 2 meV. Several different excitations are observed in the energy range of 0-60 meV (0-500 cm(-1)). In addition to acoustic phonons at low energies, we see excitations that are associated with vibrations of Li(NH3)4+ complexes. We examined these excitations as a function of momentum transfer, lithium concentration, temperature, and state of the system (solid versus liquid). Data are compared with Hartree-Fock and density-functional theory calculations of the excitations of this complex, which agree well with the measured excitation energies.
authors.affiliation: Department of Physics, Western Michigan University, Kalamazoo Michigan 49008, USA. clement.burns@wmich.edu
authors.forename: C A
authors.initials: CA
authors.lastname: Burns
authors.forename: G
authors.initials: G
authors.lastname: Vankó
authors.forename: H
authors.initials: H
authors.lastname: Sinn
authors.forename: A
authors.initials: A
authors.lastname: Alatas
authors.forename: E E
authors.initials: EE
authors.lastname: Alp
authors.forename: A
authors.initials: A
authors.lastname: Said