Phonon frequencies of lithium from a local effective potential

Abstract

Local effective electron-ion potentials for metals are constructed from a priori calculations of the electron density around an ion embedded in an electron gas. These effective potentials fold certain higher order contributions to the cohesive energy into a lower order calculation. The dynamical matrix is evaluated to second and third order in the effective potential. When band structure effects are included in the energy denominators of the response functions, the lithium phonon frequencies calculated with no empirical input are in excellent agreement with experiment.