NEW EXACT RELATIONS FOR IMPROVING THE EXCHANGE AND CORRELATION POTENTIALS

For the purpose of improving present approximations to the exchange an d correlation potentials, newly derived properties of the exact exchan ge and correlation potentials are summarized. Present approximations a re not expected to generally satisfy these properties. The summarized properties include relations at the Fermi level, low-density requireme nts, and a new density functional formula for computing ionization ene rgies. (C) 1995 John Wiley & Sons, Inc.