From newton@sunchem.chem.uga.edu Wed Jan 29 03:19:33 1997 Received: from dns1.uga.edu for newton@sunchem.chem.uga.edu by www.ccl.net (8.8.3/950822.1) id CAA08721; Wed, 29 Jan 1997 02:36:51 -0500 (EST) Received: from sunchem.chem.uga.edu (sunchem.chem.uga.edu [128.192.5.2]) by dns1.uga.edu (8.8.3/8.8.3) with ESMTP id CAA20336 for ; Wed, 29 Jan 1997 02:36:51 -0500 Received: from [168.15.176.85] (s26-pm02.athens.campus.mci.net [168.15.176.85]) by sunchem.chem.uga.edu (8.7.6/8.7.3) with SMTP id CAA26060 for ; Wed, 29 Jan 1997 02:36:58 -0500 (EST) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 29 Jan 1997 02:36:50 -0500 To: chemistry@www.ccl.net From: newton@sunchem.chem.uga.edu (newton) Subject: unsubscribe unsubscribe Can anyone tell me how to get off comp chem group? GN Gary Newton Professor, Chemistry University of Georgia Department of Chemistry Athens, GA 30602 (706)-542-1969 email: newton@sunchem.chem.uga.edu From mn1@helix.nih.gov Wed Jan 29 11:37:55 1997 Received: from helix.nih.gov for mn1@helix.nih.gov by www.ccl.net (8.8.3/950822.1) id LAA11148; Wed, 29 Jan 1997 11:06:41 -0500 (EST) Received: (from mn1@localhost) by helix.nih.gov (8.8.4/8.8.4) id LAA13395 for CHEMISTRY@www.ccl.net; Wed, 29 Jan 1997 11:06:38 -0500 (EST) Date: Wed, 29 Jan 1997 11:06:38 -0500 (EST) From: "M. Nicklaus" Message-Id: <199701291606.LAA13395@helix.nih.gov> To: CHEMISTRY@www.ccl.net Subject: G94: Problem with PES Scan in DFT Dear CCL'ers, I seem to be having a problem with a Potential Energy Surface (PES) scan in G94. I am running a relaxed PES scan on a nucleoside analog, trying to rotate the base. I am running this job at the DFT method/basis set B3LYP/6-31G(d). I'm using cartesian coordinates (a newzmat-generated input file with a Z-matrix didn't work previously), pre-optimized at the same level of theory from X-ray coordinates. For the first few conformations, everything seems to have proceeded nicely; i.e., the energy started out some 20 kcal/mol or so above the (presumed) global energy minimum, and then came down, during the partial optimization, to a reasonable value a few kcal/mol above the global min. With the current conformation, however, the job seems to be stuck, since for nearly 20 steps now, the energy has only been oscillating in a narrow band. Here's a grep of the output file (slightly modified through a filter --don't worry about the origin of the kcal/mol scale): SCF Done: E(RB+HF-LYP) = 6.587 kcal/mol ( -877.288353458 A.U.) after 12 cycles SCF Done: E(RB+HF-LYP) = 6.501 kcal/mol ( -877.288490683 A.U.) after 12 cycles SCF Done: E(RB+HF-LYP) = 6.470 kcal/mol ( -877.288539921 A.U.) after 11 cycles SCF Done: E(RB+HF-LYP) = 6.443 kcal/mol ( -877.288582731 A.U.) after 12 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288591742 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.439 kcal/mol ( -877.288590115 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288591793 A.U.) after 9 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288591832 A.U.) after 8 cycles SCF Done: E(RB+HF-LYP) = 6.440 kcal/mol ( -877.288588866 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288591957 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.439 kcal/mol ( -877.288590211 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288592040 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.440 kcal/mol ( -877.288588983 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288591984 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.440 kcal/mol ( -877.288588800 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288591901 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.439 kcal/mol ( -877.288589705 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288592037 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.440 kcal/mol ( -877.288588677 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288591887 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.439 kcal/mol ( -877.288589980 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.438 kcal/mol ( -877.288592074 A.U.) after 10 cycles SCF Done: E(RB+HF-LYP) = 6.440 kcal/mol ( -877.288588420 A.U.) after 10 cycles I'd hate to kill this job--which has already taken up ca. 20 CPU-days--if there'e any chance that it's going to converge at some reasonable time. So here are my questions: (a) Can anyone give me a hint as to what's going on here? Has anyone seen a similar behavior before? (b) Should I kill this job now, or wait a bit longer? How much longer? (c) If this is a known effect, is there anything I can do to avoid it? Marc ------------------------------------------------------------------------ Marc C. Nicklaus Lab. of Medicinal Chemistry e-mail: mn1@helix.nih.gov National Cancer Institute, NIH Phone: (301) 402-3111 Bldg 37, Rm 5B29 Fax: (301) 496-5839 BETHESDA, MD 20892-4255 USA WWW: http://www.nci.nih.gov/intra/lmch/MCNBIO.HTM ------------------------------------------------------------------------