From chemistry-request@server.ccl.net Tue Feb 13 03:17:37 2001 Received: from gate.syntem-sa.fr (gate.syntem-sa.fr [146.19.248.65]) by server.ccl.net (8.11.0/8.11.0) with ESMTP id f1D8HZw18311 for ; Tue, 13 Feb 2001 03:17:35 -0500 Received: (from uucp@localhost) by gate.syntem-sa.fr (980427.SGI.8.8.8/980728.SGI.AUTOCF) id JAA80432; Tue, 13 Feb 2001 09:14:31 +0100 (MET) Received: from syntem-sa.fr(10.0.0.2) by gate.syntem-sa.fr via smap (4.1) id xma180812; Tue, 13 Feb 01 09:14:14 +0100 Received: from victoria.syntem-sa.fr (victoria.syntem-sa.fr [10.0.0.44]) by laetitia.syntem-sa.fr (980427.SGI.8.8.8/980728.SGI.AUTOCF) via ESMTP id JAA57337; Tue, 13 Feb 2001 09:11:45 +0100 (MET) Received: from syntem-sa.fr (localhost [127.0.0.1]) by victoria.syntem-sa.fr (980427.SGI.8.8.8/980728.SGI.AUTOCF) via ESMTP id JAA11192; Tue, 13 Feb 2001 09:17:20 +0100 (MET) Sender: dturner@syntem-sa.fr Message-ID: <3A88ED90.89EC1676@syntem-sa.fr> Date: Tue, 13 Feb 2001 09:17:20 +0100 From: David Turner Reply-To: dturner@syntem.com Organization: Computational Drug Design, Syntem X-Mailer: Mozilla 4.7C-SGI [en] (X11; I; IRIX 6.5 IP32) X-Accept-Language: en MIME-Version: 1.0 To: Ivan CC: chemistry@ccl.net Subject: Re: CCL:Second negative frequency References: <003401c09484$54ceb240$71df05d4@duron-k-7> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Your second value (36 cm-1) could easily be positive given the error associated with normal mode calculations (+/-50 cm-1 or so). Perhaps you have only one imaginary frequency ... David Ivan wrote: > > Dear CCL'ers > > I am working with programme GAMESS and an present time I am facing some > problems with TS.I am simulating H-transfer from NH3 bonded to the rest of > molecule to another "free" NH3 forming "free"NH4. > In TS there are two imaginary frequencies ( 1. - value about 975, that > correspond to H-transfer and 2.- value about 36 ) and can't get rid of > this second little negative frequency. Firstly I tried to use keywords > PURIFY in $STATPT and $FORCE groups to purify hessian matrix but with no > results. Then I tried several approachs to find better TS, but all resulted > to the same TS. And IRC calculations in both directions are correct, because > according to IRC's this TS connects appropriate minimas on both side of the > hill.Finally I wanted to to perform IRC folowing the second negative > frequency, but GAMESS did not accept the specified frequency ( in $IRC > group ). > > I would very appreciate any help,advice or trick. > > Stanislav Ivan > student > > -= 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 -- ________________________________________________________________ David Turner Synt:em Senior Modeling Scientist Parc Scientifique G.Besse Computational Drug Discovery 30000 Nimes email: dturner@syntem.com France Tel: Switchboard: +33 (0)4 66 04 86 66 Fax: +33 (0)4 66 04 86 67 Direct Line: +33 (0)4 66 04 22 85 ________________________________________________________________ Discover New Drugs, Discover Synt:em http://www.syntem.com ________________________________________________________________