Popis: |
Much has been said in the very recent past about philosophy and technique of the pseudopotential method, which we regard to be the fundamental method in the area of empirical band calculations. Authoritative writers like Marvin Cohen, Volker Heine, J. C. Phillips, John Ziman, and my late friend Rolf Sandrock gave brilliant reviews (1–5), illuminating the various aspects of the work done in this field during the last ten years. Thus little can be done in the frame of this article to enhance the reputation of the pseudopotential scheme, and we will restrict ourselves to the modest aim of giving a report of recent work and of what we feel can be the impact of this method for the next future. At the beginning, however, we have to recall some of the basic ideas and formulas in order to make clear, what we are speaking about. |