From owner-chemistry@ccl.net Thu Mar 12 11:37:01 2009 From: "Yutao Yue Yutao.Yue#,#gmail.com" To: CCL Subject: CCL:G: (correction) Energy change upon swapping two orbitals in Gaussian 98 Message-Id: <-38822-090312105457-17527-GNMRUcyRUaIRAk0WnAy9kw-$-server.ccl.net> X-Original-From: "Yutao Yue" Date: Thu, 12 Mar 2009 10:54:53 -0400 Sent to CCL by: "Yutao Yue" [Yutao.Yue- -gmail.com] (sorry the energy changes are 0.02 a.u., NOT 0.2 a.u.) Dear All, I have a successful G98 single point calculation (UBLYP/6-31G*) on a metal-containing system of around 70 atoms. I use the result MOs as initial guess, but swapped the two highest occupied beta orbitals (which are supposed to be highly competing with each other) upon reading in the initial guess, to do another G98 single point calculation on the same system. I then arrived at a solution that, the frontier orbitals are almost identical to the original solution including the ordering of the beta orbitals, while the single point energy is 0.02 a.u. lower! Similar calculations was done with UBPW91/6-31G*, and again the orbitals go back to original ordering, but the single point energy is 0.02 a.u. higher now! Anybody have any idea about those energy changes? Thanks a lot and wish everybody a nice day! -Yutao Yue