A deficiency of local density functionals for the calculation of self-consistent field atomic data in plasmas

Abstract

In generating the atomic data base used in computing opacities of hot dense plasmas the local density functional approximation (LDA) is often employed. One advantage of the LDA is that the configuration average energy of a large number of ionization states and excited configurations can be computed compactly using a multi-variate Taylor series expansion in occupation numbers. The pitfalls of employing a local density functional and its impact on the quality of the Taylor series approximation are discussed. The consequences of modeling opacities with a LDA are illustrated by comparisons with experiment. A method for obviating the problems inherent in the LDA is presented.