Abstract
We present a practical method of introducing the Fermi-Dirac distribution into ab initio Green’s-function calculations. Based on a contour integration in the complex energy plane we evaluate the residues at a few Matsubara frequencies while the remaining integral is analyzed by the Sommerfeld expansion. The total energy is calculated by the grand canonical potential for which a simple formula is given. We apply the method in calculations for the Ag(001) surface and for magnetic 4d adsorbate atoms on this surface.
- Received 9 March 1995
DOI:https://doi.org/10.1103/PhysRevB.52.11502
©1995 American Physical Society