From owner-chemistry -x- at -x- ccl.net Fri Oct 14 18:49:00 2005 From: "Sengen Sun sengensun*|*yahoo.com" To: CCL Subject: CCL: Condensed Fukui Functions Message-Id: <-29616-051014182715-27711-6bGMPAXmeivE5Zxarqjj4w|*|server.ccl.net> X-Original-From: Sengen Sun Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=iso-8859-1 Date: Fri, 14 Oct 2005 14:27:06 -0700 (PDT) MIME-Version: 1.0 Sent to CCL by: Sengen Sun [sengensun**yahoo.com] There are some limitations of any FMO-derived parameters no matter how you make them mathematically. There are surely useful patterns between the reactivity and FMOs or their derived indexes. But these patterns like empirical rules do not have a definite generality, and fail from time to time as pointed by authors such as Hehre & Dewar (as I remember). Therefore, there is no cure in some cases. Any FMO-derived parameters may not be used to make any firm conclusions that cannot be experimentally verfified. Sengen ----------------------------------------- > From: b wafaa Date: Mon, 10 Oct 2005 14:51:37 +0200 (CEST) Subject: CCL: Condensed Fukui Functions Sent to CCL by: b wafaa [wafaab2=yahoo.fr] --0-1144409699-1128948697=:17669 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Dear CCLers, We have some problems in the prediction of reactivity when we calculate condensed Fukui functions with the finite difference approximation using N, N-1 and N+1 systems. In your opinion, what is the best method for the calculation of these indexes ? Which population analysis do you suggest ? Sincerely __________________________________ Start your day with Yahoo! - Make it your home page! http://www.yahoo.com/r/hs