Fwd: for ccl: Fermi and Coulomb holes

From: Pascal.Boulet;at;chiphy.unige.ch
Subject: Fwd: for ccl: Fermi and Coulomb holes
Date: Wed, 20 Feb 2002 18:41:44 +0100

 Dear CCL'ers,
 Recently, I've been asked a question about the difference between the Coulomb
 hole and the Fermi hole. Could someone give me an answer?
 Thanks in advance,
 Pascal
 ----- Forwarded message from Stephen Stackhouse
 <s.stackhouse;at;qmul.ac.uk> -----
     Date: Wed, 20 Feb 2002 17:14:39 +0000
     From: Stephen Stackhouse <s.stackhouse;at;qmul.ac.uk>
 Reply-To: Stephen Stackhouse <s.stackhouse;at;qmul.ac.uk>
  Subject: for ccl
       To: Pascal Boulet <Pascal.Boulet;at;chiphy.unige.ch>
 Pascal,
 Here is my question:
 I have recently been reading "A Chemist's Guide to Density Functional
 Theory".
 On page 26 of the book the authors discuss the Fermi hole in terms of
 pair density
 and state that "Usually the exchange hole is largest around the probe
 electron."
 Can anyone tell me why this is so? Why is it not largest at the
 reference electron,
 like the Coulomb hole?
 Stephen
 ----- End forwarded message -----