Frequency-dependent local interactions and low-energy effective models from electronic structure calculations

摘要: We propose a systematic procedure for constructing effective models of strongly correlated materials. The parameters, in particular the on-site screened Coulomb interaction $U$, are calculated from first principles, using random-phase approximation. derive an expression frequency-dependent $U(\ensuremath{\omega})$ and show, case nickel, that its high-frequency part has significant influence on spectral functions. scheme taking into account energy dependence $U(\ensuremath{\omega})$, so model with energy-independent local can still be used low-energy properties.