AB-INITIO CALCULATION OF CORRELATION EFFECTS IN METALLIC LITHIUM

Abstract

We present an ab initio calculation of the correlation effects in metallic lithium. The calculation is carried out based on the use of local operators (Local Ansatz), where correlations are included as corrections to the Hartree-Fock (HF) ground state. We investigate the strength of longer range correlations and their dependance on distance, which allows us to discuss complementary findings to LDA results. The correlation contributions to the binding energy are extracted. The missing longer range correlations can be estimated. Effects of correlations on the bulk modulus, lattice constant and charge fluctuations are analysed. The structural phases of Li with bcc- and fcc-symmetry are compared.