From owner-chemistry@ccl.net Tue Dec 11 10:47:00 2007 From: "Hemant Srivastava hemantkrsri,,gmail.com" To: CCL Subject: CCL: Strange NBO DEL Calculation Results Message-Id: <-35800-071211104528-32410-eXeb3Gw0lzi/L5RyWD4DFw!=!server.ccl.net> X-Original-From: "Hemant Srivastava" Content-Disposition: inline Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Date: Tue, 11 Dec 2007 17:45:17 +0200 MIME-Version: 1.0 Sent to CCL by: "Hemant Srivastava" [hemantkrsri*o*gmail.com] Dear Friends, I am doing NBO Del calculations, the input file is as follows ----------------------------------------------------------------------------------------------------------- %chk=c_cyc_6_reac_res1.chk %mem=120MW # HF/6-31g* scrf=(solvent=water,read,pcm) pop=(full,nbodel) choose resonance structure-1 0 1 X Y Z Radii=UAHF $NBO NBO $END $Choose LONE a 1 b 2 end BOND S 1 2 S 3 5 end $END $del nostar $End --------------------------------------------------------------------------------------------------------------------- I have made four different resonance structure of the same molecule and calculated deletion energies. Surprisingly I am getting the NBO default resonance structure higher in deletion energy than two of the structures I choose. Does anyone know if it make sense. Following is the energy of deletions of all four resonance structures. Resonance Structure-1 Energy of deletion : -1509.149678811 Resonance Structure-2 Energy of deletion : -1509.102611727 Resonance Structure-3 Energy of deletion : -1509.131159010 Resonance Structure-4 Energy of deletion : -1509.117304249 (Default Structure) Thanks in advance Hemant Srivastava The Hebrew University of Jerusalem =======================================================================