From chemistry-request@server.ccl.net Fri Apr 16 13:14:37 1999 Received: from sg1503.chemie.uni-marburg.de (root@sg1503.Chemie.Uni-Marburg.DE [137.248.151.215]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id NAA00172 for ; Fri, 16 Apr 1999 13:14:35 -0400 Received: from pc15105 (pc15105.Chemie.Uni-Marburg.DE [137.248.151.180]) by sg1503.chemie.uni-marburg.de (8.9.3/8.9.2/schn) with SMTP id NAA08006; Fri, 16 Apr 1999 13:36:31 +0200 (MEST) From: "Stefan Fau" To: Cc: Subject: RE: G94 and G98 Date: Fri, 16 Apr 1999 13:39:42 +0200 Message-ID: <001301be87fd$d1ed5460$b497f889@pc15105.chemie.uni-marburg.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 In-Reply-To: <3716B65C.1A6A3978@DKFZ-Heidelberg.de> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Importance: Normal Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by server.ccl.net id NAA00174 Dear Emad, G94 and G98 DFT differ in at least two points. 1) The default weighing scheme for the numerical integration is now Stratmann/Scuseria. It was different in G94 (the Becke scheme ?). 2) The SCF cycles are now started with a superposition of states instead of the pure guess. This _might_ lead to differences, but does not seem to be the case in your calcs. Stefan ______________________________________________________________________ Dr. Stefan Fau Fachbereich Chemie, AK Frenking Philipps-Universität Marburg 35032 Marburg, Germany fau@chemie.uni-marburg.de > -----Original Message----- > From: Computational Chemistry List [mailto:chemistry-request@ccl.net]On > Behalf Of Emadeddin Tajkhorshid > Sent: Friday, April 16, 1999 6:03 AM > To: ccl CCL > Subject: CCL:G94 and G98 > > > Dear CCL > > I have experienced something using geometry optimization in G94 and G98 > that I would like to check with you. I started from a G94-optimized set > of coordinates for glycine. Using a DFT method (B3LYP/6-31G**), on the > same platform (IBM/SP2) I started the same job in G94 and G98. These two > jobs, while having the same optimization criteria (Default values) and > the same starting geometries (and I suppose the same initial guess?) > give different results. In one case the geometry is optimized and in the > other case, the job does not meet the 'Maximum displacement' and 'RMS > displacement' criteria after the first cycle. Examination of the energy > also shows that we have different values after the first SCF. > > Although the differences in this case are not very large, I would like > to know why they happen. If I am not mistaken there are some > modifications with respect to the optimizer in G98, but I think in the > case of this example, the difference is happening at the level of > wavefunction. > > Did anybody else experience such differences at the wavefunction or > geometry level? If so, how large are they? > > > **********************G94 job************************************* > First SCF: > > SCF Done: E(RB+HF-LYP) = -284.437033067 A.U. after 15 cycles > Convg = .4529D-08 -V/T = 2.0089 > S**2 = .0000 > KE= 2.819396660737D+02 PE=-1.026794554909D+03 EE= 2.802029338205D+02 > > ::::: > Item Value Threshold Converged? > Maximum Force .000028 .000450 YES > RMS Force .000009 .000300 YES > Maximum Displacement .000293 .001800 YES > RMS Displacement .000108 .001200 YES > Predicted change in Energy=-1.479922D-08 > ****************************************************************** > > **********************G98 job************************************* > First SCF: > > SCF Done: E(RB+HF-LYP) = -284.437035418 A.U. after 15 cycles > Convg = .4595D-08 -V/T = 2.0089 > S**2 = .0000 > KE= 2.819396670445D+02 PE=-1.026794557138D+03 EE= 2.802029327275D+02 > > :::: > Maximum Force .000028 .000450 YES > RMS Force .000012 .000300 YES > Maximum Displacement .004390 .001800 NO > RMS Displacement .001377 .001200 NO > Predicted change in Energy=-7.549560D-08 > ****************************************************************** > > -- > Emad > ********************************************************************* > E. Tajkhorshid, Ph.D. > German Cancer Research Center; DKFZ Tel: +49 6221 42 2340 > Dept. Molecular Biophysics (H0200) FAX: +49 6221 42 2333 > P.O.Box 101949 http://genome.dkfz-heidelberg.de/users/emad > 69009 Heidelberg, Germany Email: E.Tajkhorshid@DKFZ-Heidelberg.de > ********************************************************************* > * "Science is talking to each other" * > ********************************************************************* > -= This is automatically added to each message by mailing script =- > CHEMISTRY@ccl.net -- To Everybody | > CHEMISTRY-REQUEST@ccl.net -- To Admins > MAILSERV@ccl.net -- HELP CHEMISTRY or HELP SEARCH > CHEMISTRY-SEARCH@ccl.net -- archive search | Gopher: > gopher.ccl.net 70 > Ftp: ftp.ccl.net | WWW: http://www.ccl.net/chemistry/ | Jan: > jkl@ccl.net > >