From owner-chemistry@ccl.net Mon Oct 18 06:01:00 2010 From: "Heng Zhang chemzhh(!)163.com" To: CCL Subject: CCL: questions about how to optimize a large system efficiently Message-Id: <-42972-101018055915-29905-P8kL3WMZvVRsvCjv3vv8LA##server.ccl.net> X-Original-From: "Heng Zhang" Date: Mon, 18 Oct 2010 05:59:14 -0400 Sent to CCL by: "Heng Zhang" [chemzhh/a\163.com] Dear All, Now I am optimizing a large system. I have two questions as following: 1 If I use small basis (such as 3-21g, etc.) to do the optimization first, then use the optimized structure as the initial structure and do optimization again with large basis (such as 6-31g, etc.). Is this is OK for saving computation time? I am wandering whether the first optimization using small basis would get wrong results and the initial structure from the first optimization is not good for the second optimization. 2 Which one is better as to the idea of whether optimizing real system using small basis or optimizing simplified system (such as using PMe3 instead of PPh3) using large basis? Thanks in advance Heng From owner-chemistry@ccl.net Mon Oct 18 07:09:00 2010 From: "Vincent Xianlong Wang xloongw^yahoo.com" To: CCL Subject: CCL:G: Problem in SCIPCM Optimization Message-Id: <-42973-101018070625-5761-d3ON+6g66LYFSR1o1IzR9g!^!server.ccl.net> X-Original-From: Vincent Xianlong Wang Content-Type: text/plain; charset=us-ascii Date: Mon, 18 Oct 2010 04:05:51 -0700 (PDT) MIME-Version: 1.0 Sent to CCL by: Vincent Xianlong Wang [xloongw++yahoo.com] Hi, I guess you have a redundant newline break in the connectivity section of your input file: "1 2 1.5 6 1.5 8 \n 1.0" should be on the same line, "1 2 1.5 6 1.5 8 1.0" Vincent ----- Original Message ---- > From: Guilherme Lu s Cordeiro guilhermecord(!)gmail.com To: "Wang, Xianlong " Sent: Sat, October 16, 2010 10:31:13 PM Subject: CCL:G: Problem in SCIPCM Optimization Sent to CCL by: "Guilherme Lu s Cordeiro" [guilhermecord#,#gmail.com] Dear CCL members, I am trying to perform a flavonoid optmization in ethanolic solution, but I got a problem while doing it. Part of my input data was as follows: %mem=6MW %nproc=1 %chk=QUER.ch ----------------------------------------- #T B3LYP/6-31G(d,p) SCRF(SCIPCM) Opt Test ----------------------------------------- -------------------- Quercetin in Ethanol -------------------- Symbolic Z-matrix: Charge = 0 Multiplicity = 1 The output shows the following error: Rotational constants (GHZ): 0.5907837 0.1401203 0.1132581 Isotopes: C-12,C-12,C-12,C-12,O-16,C-12,O-16,O-16,O-16,C-12,C-12,C-12,C-12,H-1,O -16,H-1,C-12,C-12,C-12,C-12,C-12,C-12,H-1,O-16,O-16,H-1,H-1,H-1,H-1,H-1,H-1,H-1 380 basis functions 686 primitive gaussians 78 alpha electrons 78 beta electrons nuclear repulsion energy 1690.1211869024 Hartrees. Projected INDO Guess. Integral accuracy reduced to 1.0D-05 until final iterations. WANTED AN INTEGER AS INPUT. FOUND A FLOATING POINT NUMBER AS INPUT. 1 2 1.5 6 1.5 8 1.0 ? Error termination via Lnk1e in C:\G98W\l502.exe. I would like any help. Thanks.http://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt