From jerry@dft.chem.cuhk.hk Thu May 30 00:50:33 1996 Received: from iris.chem.cuhk.hk for jerry@dft.chem.cuhk.hk by www.ccl.net (8.7.5/950822.1) id AAA07580; Thu, 30 May 1996 00:00:05 -0400 (EDT) Received: from dft.chem.cuhk.hk by iris.chem.cuhk.hk via SMTP (931110.SGI/940406.SGI.AUTO) for chemistry@www.ccl.net id AA25656; Thu, 30 May 96 11:59:29 +0800 Received: by dft (950511.SGI.8.6.12.PATCH526/930416.SGI.AUTO) id LAA01330; Thu, 30 May 1996 11:59:27 +0800 Date: Thu, 30 May 1996 11:59:27 +0800 (HKT) From: Jerry C C Chan To: chemistry@www.ccl.net Subject: Summary: Experimental or Optimized Structures Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear Netters, Two weeks ago I posted a question on the following issues: 1. Absolute shielding is considered as the best measure of the quality of calculated shielding tensor components. Why not chemical shift anisotropy and eta? 2. Since the experimental CSA and eta "contain" the effects of the environment, should one choose the experimental geometry rather than trying to optimized the geometry of the species when the absolute shielding scale is not available. The enlightening responses from Robert and Georg are greatly appreciated. Below please find the responses received. Jerry, The Chinese University of Hong Kong ***************** My bet is that most will tell you to use the experimental geometry but I would advocate a high level ab initio optimized geometry. X-ray results are influenced by crystal packing which distort the geometry to some extent. You usually do the NMR shielding calc in vacume so why not have a vacume geometry. Thsi should be obtained from a decent search and minimization at a theoretical level comparable to that at which you will do the NMR shielding calc at. Thank-you Robert A. Kirby BioChem Therapeutiques Inc. 275 Armand-Frappier Blvd. Laval, Quebec, H7V 4A7 kirbyr@biochem-pharma.com ***************** > 1. Absolute shielding is considered as the best measure of the quality of > calculated shielding tensor components. Why not chemical shift anisotropy > and eta? Those two are undoubtely also good measures for the quality of your calculation -- if you have the experimental results. Shieldings are often used because there is always the possibility that some systematic error remains hidden in relative shift if it happens to cancel out. > 2. Since the experimental CSA and eta "contain" the effects of the > environment, should one choose the experimental geometry rather than > trying to optimized the geometry of the species when the absolute > shielding scale is not available. If you have a GOOD experimental structure, than it is probably preferable. I stress the word "good" here since the shielding is extremely sensitive to small changes in the geometry (this in turn is just one of the reasons why experimentalists do NMR measurements). However, in many cases of interest, you don't have such structures, or not for the whole set of molecules that you are studying. In these cases, calculated structures are your choice. Some people use exclusively optimized structures since this provides a consistent picture. Yours, Georg P.S. I am looking forward to your summary. ============================================================================== Georg Schreckenbach Tel: (Canada)-403-220 8204 Department of Chemistry FAX: (Canada)-403-289 9488 University of Calgary Email: schrecke@zinc.chem.ucalgary.ca 2500 University Drive N.W., Calgary, Alberta, Canada, T2N 1N4 ============================================================================== >From boyd@chem.iupui.edu Wed May 29 17:34 EDT 1996 Received: from indyvax.iupui.edu for boyd@chem.iupui.edu by www.ccl.net (8.7.5/950822.1) id RAA05765; Wed, 29 May 1996 17:34:49 -0400 (EDT) Received: from macgw.chem.iupui.edu by INDYVAX.IUPUI.EDU (PMDF V5.0-5 #5862) id <01I5A956KA6O00A246@INDYVAX.IUPUI.EDU> for chemistry@www.ccl.net; Wed, 29 May 1996 16:30:42 -0500 Date: Wed, 29 May 1996 16:25:02 -0500 From: Boyd Subject: FREE BOOKS To: OSC CCL Message-id: X-Mailer: Mail*Link SMTP-MS 3.0.2 Content-transfer-encoding: 7BIT Content-Type: text Content-Length: 1373 Status: R Dear CCLers, We are pleased to announce the 1995 winners in the contest offered on the "Reviews in Computational Chemistry" home page: Prof. Christopher J. Cramer (University of Minnesota) and Prof. Helder M. Marques (University of Witwatersrand). Each had 6 or more citations to chapters from "Reviews in Computational Chemistry" in their 1995 journal articles. Each is being awarded a free volume of "Reviews in Computational Chemistry". Congratulations, Chris and Helder! We thank everyone who entered the contest this spring. Remember that awards will made next spring based on citations to "Reviews in Computational Chemistry" in 1996 journal articles. Another give-away currently being offered on the "Reviews in Computational Chemistry" home page is for teachers who use the books in conjunction with their classes. Details are given on the home page. We wish everyone good luck in all the give-aways. Sincerely, Don Donald B. Boyd, Ph.D. Research Professor of Chemistry Co-Editor, REVIEWS IN COMPUTATIONAL CHEMISTRY Department of Chemistry Indiana University-Purdue University at Indianapolis 402 North Blackford Street Indianapolis, Indiana 46202-3274, U.S.A. Telephone 317-274-6891 Facsimile 317-274-4701 Internet boyd@chem.iupui.edu REVIEWS IN COMPUTATIONAL CHEMISTRY Home Page on the World Wide Web URL http://chem.iupui.edu/~boyd/rcc.html >From gaussian.com!moses@lorentzian.com Tue May 28 13:14 EDT 1996 Received: from relay5.UU.NET for gaussian.com!moses@lorentzian.com by www.ccl.net (8.7.5/950822.1) id NAA21902; Tue, 28 May 1996 13:14:09 -0400 (EDT) Received: from uucp1.UU.NET by relay5.UU.NET with SMTP (peer crosschecked as: uucp1.UU.NET [192.48.96.32]) id QQarrg22220; Tue, 28 May 1996 13:14:03 -0400 (EDT) Received: from m10.UUCP by uucp1.UU.NET with UUCP/RMAIL ; Tue, 28 May 1996 13:14:05 -0400 Received: by m10.lorentzian.com; Tue, 28 May 1996 12:31:20 -0400 Received: by mousse.gaussian.com; Tue, 28 May 1996 11:23:23 -0400 Message-Id: From: gaussian.com!moses@lorentzian.com (David Moses) Subject: G94 available on new SGI platforms To: CHEMISTRY@www.ccl.net Date: Tue, 28 May 1996 11:23:22 -0400 (EDT) X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII Content-Length: 2336 Status: RO Dear Colleague: Gaussian, Inc is pleased to announce the availability of Gaussian 94 for SGI R10000 and R5000 systems. These versions have been tested under SGI Irix and Fortran version 6.2. With this announcement, we now distribute Gaussian 94 for the following computer platforms and operating systems: Gaussian 94 ----------- Convex C-Series (ConvexOS) and SPP (SPP-UX) Cray C90, YMP, XMP and J90 (UniCOS) DEC Alpha AXP (OSF1 and OpenVMS) Fujitsu VP, VPX, VPP500 and M Series (UXP/M) Hitachi S3600, S3800 (HI-OSF/1-MJ) and SR2201 (HI-UX/MPP, Single Node) HP-700 (HP-UX) IBM RS/6000 (AIX) Intel 486 and Pentium Processors (FreeBSD and Linux) NEC SX-3 and SX-4 (SuperUX) Silicon Graphics R4000, R5000, R8000, R10000 (IRIX) Sun (Solaris and SunOS) Gaussian 94W (executable-only, single machine license) ------------------------------------------------------ Intel 486 and Pentium Processors (Windows 3.1 and Windows 95) We remind users that we maintain a mailing list for those interested in subscribing to our free newsletter, Gaussian NEWS. The newsletter discusses new implementations, updates, and future developments of the Gaussian system of programs. It also informs subscribers about upcoming user meetings and workshops, and contains features such as user profiles and technical notes. To subscribe to Gaussian NEWS, please e-mail your full postal address to info@gaussian.com. For additional information regarding the Gaussian system of programs, please to contact us at the address, telephone numbers (voice or facsimile), or electronic mail given below. *------------------------*------------------------*-----------------------* | David J. Moses, Ph.D. | Carnegie Office Park | info@gaussian.com | | Vice President, C.O.O. | Building Six | 412-279-6700 (Voice) | | Gaussian, Inc. | Pittsburgh, PA 15106 | 412-279-2118 (FAX) | *------------------------*------------------------*-----------------------* This notice is sent without warranty of any kind, expressed or implied. Gaussian is a registered trademark of Gaussian, Inc. All other trademarks are the property of their respective holders. Specifications and availability subject to change without notice. From tgm@SSD.intel.com Thu May 30 02:50:35 1996 Received: from SSD.intel.com for tgm@SSD.intel.com by www.ccl.net (8.7.5/950822.1) id CAA08119; Thu, 30 May 1996 02:01:35 -0400 (EDT) Received: from idaho.SSD.intel.com by SSD.intel.com (4.1/SMI-4.1) id AA17184; Wed, 29 May 96 23:00:27 PDT Received: by idaho.SSD.intel.com (4.1/SMI-4.1) id AA01453; Wed, 29 May 96 23:00:27 PDT Date: Wed, 29 May 96 23:00:27 PDT From: "Timothy G. Mattson" Message-Id: <9605300600.AA01453@idaho.SSD.intel.com> To: bernhold@npac.syr.edu, tgm@SSD.intel.com Subject: Re: CCL:Symposium CFP - Cluster and MPP computing Cc: CHEMISTRY@www.ccl.net > > Hi Tim, I definitely plan to submit something, though I hate these long > lead times. (I know they're not your fault.) > > Best, David > David, I'm glad to hear that you're interested in submitting something for the sympossium. I'll put you on the sympossium mailing list. --Tim From scnit.saratov.su!uucp@scnit.saratov.su Thu May 30 03:50:34 1996 Received: from sgu.ssu.runnet.ru for scnit.saratov.su!uucp@scnit.saratov.su by www.ccl.net (8.7.5/950822.1) id DAA09825; Thu, 30 May 1996 03:33:58 -0400 (EDT) Received: from scnit.UUCP (uuscnit@localhost) by sgu.ssu.runnet.ru (8.6.12/8.6.12) with UUCP id LAA29774 for chemistry@www.ccl.net; Thu, 30 May 1996 11:27:16 +0400 Received: by scnit.saratov.su (UUPC/@ v6.17, 30Apr96) id AA28629; Thu, 30 May 1996 10:42:20 +0400 (MSD) To: chemistry@www.ccl.net Message-Id: Organization: Saratov Atate University From: "pankratov" Date: Thu, 30 May 96 10:42:20 +0400 X-Mailer: BML [MS/DOS Beauty Mail v1.36H] Subject: The ways to reach a minimum within MOPAC calculations Lines: 22 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii May 30, 1996 Professor Sharifuddin Mohd Zain Jabatan Kimia University Malaya Malaysia Dear Professor Mohd Zain, According to our small experience, the ways to avoid a negative force constant appearance, as well as to reach a sufficient gradi- ent norm decrease, consist in using NLLSQ (as you consider), the latter often increasing the computational time drastically, and also applying NOTHIEL, DFP, or NOTHIEL and DFP together. Sincerely yours Alexei Pankratov Professor Dr. Sc. Alexei N. Pankratov Department of Chemistry N. G. Chernyshevskii Saratov State University 83 Astrakhanskaya Street, Saratov 410071, Russia Fax: ++7 (8452) 24-04-46 E-mail: pankratov@scnit.saratov.su From chpajt@bath.ac.uk Thu May 30 05:50:35 1996 Received: from goggins.bath.ac.uk for chpajt@bath.ac.uk by www.ccl.net (8.7.5/950822.1) id FAA10303; Thu, 30 May 1996 05:18:42 -0400 (EDT) Received: from bath.ac.uk (actually host midge.bath.ac.uk) by goggins.bath.ac.uk with SMTP (PP); Thu, 30 May 1996 10:16:29 +0100 Date: Thu, 30 May 1996 10:16:22 +0100 (BST) From: A J Turner To: pankratov cc: chemistry@www.ccl.net Subject: Re: CCL:M:The ways to reach a minimum within MOPAC calculations In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi! I did not catch the start of this - but I have found that there can be a problem with negative force constants. My solution is equally computer intensive, I use an explicit hessian calculation intiated bakers mimimisation ef hess=1 or ef hess=3 let ddmin=0.0 ddmax=0.05 may also be of use - but even more expencive. Kind regards Alex +--------------------------------------------------+ |Alternate E-mail A.J.Turner@Bath.ac.uk | |www home @ http://www.bath.ac.uk/~chpajt/home.html| +--------------------------------------------------+ From joubert@ext.jussieu.fr Thu May 30 05:57:07 1996 Received: from shiva.jussieu.fr for joubert@ext.jussieu.fr by www.ccl.net (8.7.5/950822.1) id FAA10347; Thu, 30 May 1996 05:33:04 -0400 (EDT) Received: from idf.ext.jussieu.fr (idf.ext.jussieu.fr [134.157.81.129]) by shiva.jussieu.fr (8.7.5/jtpda-5.2) with ESMTP id LAA10767 for ; Thu, 30 May 1996 11:33:04 +0200 (METDST) Received: from [134.157.11.17] by idf.ext.jussieu.fr (8.6.10/jtpda-4.0) with SMTP; Thu, 30 May 1996 11:33:03 +0200 X-Sender: joubert@idf.ext.jussieu.fr Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 30 May 1996 11:35:45 +0200 To: chemistry@www.ccl.net From: joubert@ext.jussieu.fr (Laurent Joubert) Subject: ECP with lmax=5 (G94) Dear Netters, I'm actually doing some calculations on Hf compounds, using Stuttgart's ECPs. But I have a problem with Hf ECP. For this atom, lmax=5 and Gaussian 94 creates this error : OPERATION ON FILE OUT OF RANGE. FILEIO: IOPER= 1 IFILNO(1)= -582 LEN= 120 IPOS= 0 Q= 27063700 For Zr, with lmax=4, I don't have any problem. Thanks in advance for your answers. Laurent Joubert ------------------------------------------------------------------ Laurent JOUBERT (PhD student) Ecole Nationale Superieure de Chimie de Paris Laboratoire d'Electrochimie et de Chimie Analytique 11, rue Pierre et Marie Curie 75231 PARIS CEDEX 05- FRANCE Tel : 44-27-66-94 Fax : 44-27-67-50 E-Mail : joubert@ext.jussieu.fr WWW site : http://www.enscp.jussieu.fr ------------------------------------------------------------------ From ncapron@ccr.jussieu.fr Thu May 30 07:50:36 1996 Received: from shiva.jussieu.fr for ncapron@ccr.jussieu.fr by www.ccl.net (8.7.5/950822.1) id HAA10963; Thu, 30 May 1996 07:36:47 -0400 (EDT) Received: from moka.ccr.jussieu.fr (moka.ccr.jussieu.fr [134.157.1.23]) by shiva.jussieu.fr (8.7.5/jtpda-5.2) with ESMTP id NAA18683 for ; Thu, 30 May 1996 13:36:47 +0200 (METDST) Received: from (ncapron@localhost) by moka.ccr.jussieu.fr (8.7.5/jtpda-5.2) id NAA40946 for chemistry@www.ccl.net; Thu, 30 May 1996 13:36:47 +0200 From: ncapron@ccr.jussieu.fr (Nathalie CAPRON) Message-Id: <199605301136.NAA40946@moka.ccr.jussieu.fr> Subject: beta-tin structure To: chemistry@www.ccl.net Date: Thu, 30 May 1996 13:36:47 +0200 (DST) X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit Dear All, I should need more information about a crystallographic structure It must be something very easy for a cristallographer but I have some trouble with the beta tin structure. Indeed, I saw it is tetragonal with a certain value of the ratio c/a, in the case of Sn. But if this structure is applied to pure silicon do we have still this structrure or does it become body-centered tetragonal ? In one word : which is the beta tin structure for the silicon ? Thanks for all your responses Nathalie Capron Laboratoire de Chimie Physique 11, rue Pierre et Marie Curie 75005 Paris France ncapron@ccr.jussieu.fr From toukie@zui.unizh.ch Thu May 30 12:50:46 1996 Received: from rzusuntk.unizh.ch for toukie@zui.unizh.ch by www.ccl.net (8.7.5/950822.1) id LAA12176; Thu, 30 May 1996 11:52:15 -0400 (EDT) From: Received: from rzurs4.unizh.ch by rzusuntk.unizh.ch (4.1/SMI-4.1.9) id AA13400; Thu, 30 May 96 17:51:57 +0200 Received: by rzurs4.unizh.ch (AIX 3.2/UCB 5.64/4.03) id AA73974; Thu, 30 May 1996 17:51:56 +0200 Message-Id: <9605301551.AA73974@rzurs4.unizh.ch> Subject: Znc phenolate To: chemistry@www.ccl.net Date: Thu, 30 May 1996 17:51:56 +0200 (MEST) X-Mailer: ELM [version 2.4 PL24 PGP2] Content-Type: text Dear Colleagues; I am curious about the possibility (or impossibility) of forming zinc phenolate complexes (permanent or transiemt) in an aqueous solution of phenol and a soluble zinc salt (e.g. ZnCl2). If anyone has some thoughts on the matter I would be grateful to hear from you. Thanks in advance to all responders. Sincerely, S. Shapiro toukie@zui.unizh.ch From rameshg@umich.edu Thu May 30 17:50:43 1996 Received: from stargate.rs.itd.umich.edu for rameshg@umich.edu by www.ccl.net (8.7.5/950822.1) id RAA13628; Thu, 30 May 1996 17:21:20 -0400 (EDT) Received: from stargate.rs.itd.umich.edu by stargate.rs.itd.umich.edu (8.7.1/2.2) id RAA00983; Thu, 30 May 1996 17:21:13 -0400 (EDT) Date: Thu, 30 May 1996 17:21:11 -0400 (EDT) From: Ramesh Gopalaswamy X-Sender: rameshg@stargate.rs.itd.umich.edu To: Comp Chem List Subject: saddle calculations-summary Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII My sincere thanks to all who helped me with their valuable suggestions on 'saddle' routine and TS optimzation. Here's a summary of replies....... ****************************************************************************** > Hello CCLers, > Could someone give me some pointers on SADDLE calculations > to locate TS and what to do further on it - refining the TS and force > calculations etc. Any tips on useful keywords are welcome. > Thanks so much. > > Ramesh >From kcousins@wiley.csusb.eduThu May 23 16:51:33 1996 Date: Thu, 23 May 1996 11:46:58 -0700 (PDT) From: Kimberley Cousins To: rameshg@centipede.rs.itd.umich.edu Subject: saddle calcs Hi. You didn't mention if you were using AMPAC/MOPAC or what (although I asssume that you are). I've used SADDLE in the past in these programs to search for a TS with mixed success. I now usually make a guess at a TS structure instead of using this command. I then use something like NLLSQ or SIGMA to locate the closest stationary point. If I've guessed well that point is the TS(exactly one negative eigenvalue in the resulting force matrix). If you insist on using SADDLE, depending on the coordinates chosen for starting material(s) and product(s) you may find an approximate TS geometry that you will then use with NLLSQ or SIGMA (or another routine depending on which version of which program you are using!) Kimberley Cousins Department of Chemistry California State University, San Bernardino 5500 University Parkway San Bernardino, CA 92407 (909)880-5391 kcousins@wiley.csusb.edu From chreties@CHIMCN.UMontreal.CAThu May 23 16:53:06 1996 Date: Thu, 23 May 1996 14:46:40 -0400 (EDT) From: Chretien Steeve To: rameshg@centipede.rs.itd.umich.edu Cc: Chretien Steeve Subject: Transition state determination Hi, I am a graduate student in theoritical chemistry in the researh group of Dr Dennis R. Salahub at Universite de Montreal. You can take a look at the articles below which talk about many methods. (1) Klaus Muller, Angewandte chemie, vol. 19, 1980, p.1-13 (2) Y. Abashkin and Nino Russo, J. Chem. Phys., vol. 100, 1994, p.4477-83 I hope that this references will help you. Best regard Steeve Chretien From jpcannady@dcrn.e-mail.comThu May 23 16:56:51 1996 Date: Thu, 23 May 1996 15:37:22 EDT From: jpcannady@dcrn.e-mail.com To: rameshg@umich.edu Subject: CCL:Saddle calculations Ramesh, you don't specifically mention that you are using MOPAC, but I suspect you are. If this is the case, then, take the geometry of the output from the saddle (best guess of TS geometry) as the input to a job with the keyword NLLSQ or TS or SIGMA. Each of these is slightly different, but allows optimization of stationary points that are not minima. It is possible that the optimizer will "find" one of the minima, rather than the TS. Compare the output geometry and energy to see if it stayed "near" the saddle output. If it has, then you MUST run FORCE calculation on that refined geometry (not on the output of the SADDLE calculation). If all is well, you will find that 1) the gradient is small enough for a FORCE calculation, and bfgs optimizer will not be invoked and 2) that there is one and only one "negative" (actually imaginary) frequency, corresponding to one and only one negative eigenvalue of the Hessian (force constant matrix). If this is the case, then you have indeed found a 1st order saddle point, or transition state. In my experience, it is important to then follow this up with two more runs. Both start at the refined TS geometry, but use the keyword IRC=1 in one and IRC=-1 in the other. You should also use the keywords LARGE and X-PRIO for these runs. The output should show the energy and the geometry proceding from the TS to the reactant, and the product. If the endpoints of the IRC runs are in fact your intended reactant and product, then you have found a transition state connecting the two. What you don't know yet is whether this is the lowest energy TS between these two points on the potential energy surface. For that, you get to keep searching, using the same techniques, but testing out different potential reactant geometries, etc. Pat From newhoir@duc.auburn.eduThu May 23 17:03:55 1996 Date: Thu, 23 May 1996 15:16:52 -0500 From: Irene Newhouse To: rameshg@centipede.rs.itd.umich.edu Subject: RE: SADDLE These comments refer to SADDLE as implented in MOPAC: It's a touchy routine & often crashes, even with small molecules. I've had MUCH better luck by starting from product & doing a reaction coordinate to pull it apart into reactants. Select out the structure with the highest energy & refine using keywords like NLLSQ. If that doesn't work, freeze the critical coordinates, optimize around them & then unfreeze & do NLLSQ. Check your results by doing a frequency computation & animating the frequencies to see if the largest motion of the "negative" frequency [there should be only 1] corresponds to the reaction. You should also do a DRC, but that's tricky, too. TS keyword in MOPAC is alleged to be the greatest thing since sliced bread. Not so! 90% of the time it goes to a product with no negative eigenvalues in the force constant matrix in spite of the fact that it's supposed to track along the reaction coordinate only. Once it found a transition state for me, but not for the reaction I wanted. I never did figure out what reaction it was for! If these general things don't help enough, maybe you could write me more about what you're trying to do & I could see if I could provide more concrete sug- gestions. Irene Newhouse From jpcannady@dcrn.e-mail.comFri May 24 11:50:36 1996 Date: Thu, 23 May 1996 21:24:14 EDT From: jpcannady@dcrn.e-mail.com To: rameshg@umich.edu Subject: Re: CCL:Saddle calculations Generally, I look at the z-matrices and compare the geometric parameters. Usually, if the optimizer has taken the system to one of the minima, instead of the TS, there will be a VERY close match (less than 1% difference) between each corresponding value. There do exist in some software packages "overlay" or "comparison" modules, but, there is usually no need. If the nllsq or ts or sigma optimizer winds up somewhere else (not one of the two minima) and the heat of formation is more positive than either of the minima (may be close to the heat of formation for the saddle point, or may be tens of kcal/mol away), I would go ahead and do the force calculation to test for the one and only imaginary frequency. It may not be terribly scientific, but, then, my experience and the teachings of those with even more experience says that finding TS's is still something of an art. On the other hand, finding TS's and corresponding estimates of Ea's is one of the more rewarding things to do in this field, so keep on going! Pat From chmcws@leonis.nus.sgFri May 24 11:54:07 1996 Date: Fri, 24 May 1996 14:25:35 +0800 (SST) From: Chin Wee Shong To: rameshg@umich.edu Cc: W S Chin Subject: Saddle calculations Hi Ramesh, I have some experience before with SADDLE, it never worked - the optimized geometries did not give one and only one negative force constant. We are now using Eigenvalue following (EF) procedure, it is much more promising. All you need to do is to give a fair guess of the structure of the transition state - usually intermediate of your starting and end molecules. Wish you luck, Chin W S From Jeffrey.Gosper@brunel.ac.ukFri May 24 11:57:58 1996 Date: Fri, 24 May 1996 11:41:38 BST From: Jeffrey J Gosper To: Ramesh Gopalaswamy Subject: Re: CCL:Saddle calculations > Have a look at http://www.caos.kun.nl/~borkent/compcourse/comp.html and http://www.brunel.ac.uk/depts/chem/ch241s/re_view/re_view.htm for information on these topics. Please summaries your responses for the CCL. /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Dr. Jeff Gosper Dept. of Chemistry BRUNEL University Uxbridge Middx UB8 3PH, UK voice: 01895 274000 x2187 facsim: 01895 256844 internet/email/work: Jeffrey.Gosper@brunel.ac.uk internet/WWW: http://http1.brunel.ac.uk:8080/~castjjg Re_View's Home page (A molecular display/animation/analysis program): http://http1.brunel.ac.uk:8080/depts/chem/ch241s/re_view/re_view.htm \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ From ryszard@msi.comFri May 24 11:58:37 1996 Date: Fri, 24 May 1996 10:09:35 -0400 (EDT) From: Ryszard Czerminski To: Ramesh Gopalaswamy Subject: Re: CCL:Saddle calculations Some time ago I have been using routines from GAMESS for this purpose. I found them very robust and well documented. Ryszard .................................. Ryszard Czerminski Molecular Simulations Incorporated 16 New England Executive Park Burlington, MA 01803-5297 tel: (617)229-8875 x 217 fax: (617)229-9899 e-mail: ryszard@msi.com