CCL: Announce: XCFun DFT library

 Sent to CCL by: =?ISO-8859-1?Q?Ulf_Ekström?= [ulfek#,#few.vu.nl]
 Dear All,
 we are happy to announce the XCFun arbitrary-order exchange-
 correlation functional library. We use automatic differentiation to
 provide arbitrary order derivatives from an implementation of the
 exchange-correlation energy. Therefore this library is very easy to
 use for development of new functionals, as well as using existing
 functionals for various kinds of perturbation theory.  The library
 is free software, and we have already implemented many of the
 popular functionals. External contributions are very welcome!
 If it sounds interesting you may have a look at our recent JCTC
 publication "Arbitrary-Order Density Functional Response Theory
 > from Automatic Differentiation" U. Ekström, L. Visscher, R. Bast,
 A.J. Thorvaldsen and Kenneth Ruud  May 24, 2010 DOI: 10.1021/ct100117s
 or the project website (with links for source code download):
 http://admol.org/xcfun
 Sincerely,
 Ulf Ekström