Computation of electronic chemical potentials using free energy density functionals

An iterative scheme based on a finite temperature free energy density functional, originally developed for the study of bulk metals, is applied to compute the electronic chemical potential of liquid water. By way of validation of this approach, we have also investigated the chemical potential and HOMO and LUMO eigenvalues of two finite systems, the O atom and F-2 molecule, as a function of fractional charge. The results are anlalysed in terms of the Perdew, Parr, Levy and Balduz theorems. Special attention is paid to the role and interpretation of integer derivative discontinuities for the exchange correlation functional (BLYP) that is used. (C) 2000 Elsevier Science B.V. All rights reserved.