From chemistry-request ^at^ server.ccl.net Mon Apr 26 07:28:37 1999 Received: from neon.ch.pwr.wroc.pl (neon.ch.pwr.wroc.pl [156.17.2.212]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id HAA32330 for ; Mon, 26 Apr 1999 07:28:14 -0400 Received: from neon.ch.pwr.wroc.pl (localhost [127.0.0.1]) by neon.ch.pwr.wroc.pl (980427.SGI.8.8.8/970903.SGI.AUTOCF) via SMTP id MAA01260 for ; Mon, 26 Apr 1999 12:13:19 +0200 (MDT) Sender: jola $#at#$ neon.ch.pwr.wroc.pl Message-ID: <37243C3F.794B -A_T- neon.ch.pwr.wroc.pl> Date: Mon, 26 Apr 1999 12:13:19 +0200 From: Jolanta Grembecka Organization: Wroclaw University of Technology X-Mailer: Mozilla 3.01SGoldC-SGI (X11; I; IRIX 6.3 IP32) MIME-Version: 1.0 To: chemistry |-at-| server.ccl.net Subject: convergence Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Dear CCLers, I would like to perform an optimization of inhibitor in the active site of the enzyme, using ONIOM in Gaussian98. Some of the enzyme active site fragments are frozen, while others as well as inhibitor are free to move. However, there is a problem with convergence in third step of the optimization. This is a fragment from the output file: ------------ GradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGrad Berny optimization. Use GDIIS/GDPIS optimizer. Internal Forces: Max 0.122271245 RMS 0.022900677 Search for a local minimum. Step number 3 out of a maximum of 390 All quantities printed in internal units (Hartrees-Bohrs-Radians) Swaping is turned off. 2 1 -0.2994080E-01 0.1587312 0.1886258 Update second derivatives using information from points 2 3 Trust test= 3.55D+00 RLast= 2.67D+00 DXMaxT set to 6.00D-01 RFO step: Lambda= 3.07895529D-02. Cosine: 0.361 < 0.866 Cut down GDIIS temporarily because of the cosine check. E 7 Maximum step size ( 0.600) exceeded in Quadratic search. -- Step size scaled by 0.923 SLEqS1 Cycle: 1951 Max:0.182663E-01 RMS:0.288751E-02 Conv:0.830925E-06 SLEqS1 Cycle: 1951 Max:0.547130 RMS:0.725821E-01 Conv:0.830925E-06 Iteration 1 RMS(Cart)= 0.07678248 RMS(Int)= 0.04090075 SLEqS1 Cycle: 1951 Max:0.309281 RMS:0.644244E-01 Conv:0.348998E-06 SLEqS1 Cycle: 1951 Max:0.103404 RMS:0.178235E-01 Conv:0.348998E-06 Iteration 2 RMS(Cart)= 0.03887554 RMS(Int)= 0.01798566 SLEqS1 Cycle: 1951 Max:0.210165 RMS:0.233334E-01 Conv:0.229509E-06 SLEqS1 Cycle: 1951 Max:0.573045 RMS:0.728841E-01 Conv:0.229509E-06 . . . . . (the lattest iteration) Iteration 99 RMS(Cart)= 0.04352782 RMS(Int)= 3.41598486 SLEqS1 Cycle: 1951 Max:0.400389E-02 RMS:0.688668E-03 Conv:0.200000E-06 SLEqS1 Cycle: 1951 Max:0.145725E-01 RMS:0.184286E-02 Conv:0.200000E-06 Iteration100 RMS(Cart)= 0.02664367 RMS(Int)= 3.39771394 Curvilinear step not converged. Error imposing constraints Error termination via Lnk1e in /d2/PROGRAMY/g98/l103.exe. -------------------- How to resolve this problem? Jola Grembecka Institute of Organic Chemistry, Biochemistry and Biotechnology Wroclaw University of Technology