*From*: John Merle <jkmerle-.-yahoo.com>*Subject*: CCL:G: HR problem with G03: Problem with the number of degrees of freedom*Date*: Tue, 23 Sep 2008 12:45:28 -0700 (PDT)

Sent to CCL by: John Merle [jkmerle]_[yahoo.com] Yangsoo, I have done some work in this area and my general impression regarding thermal corrections due to hindered rotors is not a simple problem and when molecules have many degrees of freedom (e.g., long chain alkanes) the problem is very complex. In my experience Gaussian has a difficult time identifying hindered rotor in all but the simplest cases (e.g., 1 methyl group). The best way to identify them is manually. Then you can calculate the potential surface of the bond rotation to confirm whether or not you should treat it as a hindered rotor. Once identified you can use the Pitzer / Gwynn tables to determine the correction. Several groups also determine the corrections theoretically. I know Joe Bozzelli at the New Jersey Institute of Tech. does this a lot. I remember using some code from John Barker's (U. Mich.) Multiwell program as well. John Merle --- On Tue, 9/23/08, Yangsoo Kim vsmember*_*gmail.com <owner-chemistry###ccl.net> wrote: > From: Yangsoo Kim vsmember*_*gmail.com <owner-chemistry###ccl.net> > Subject: CCL:G: HR problem with G03: Problem with the number of degrees of freedom > To: "Merle, John K " <jkmerle###yahoo.com> > Date: Tuesday, September 23, 2008, 4:40 AM > Sent to CCL by: "Yangsoo Kim" > [vsmember:+:gmail.com] > Dear All, > > A while ago, I posted a problem on hindered rotor > calculation with G03, > which is the one that other users also have. The related > CCL posts on the > problems are attached below. Basically, G03 terminated with > the error > message "Problem with the number of degrees of > freedom", when molecules > other than alkane are calculated for hindered rotor > analysis. > > I wonder if there is any clue that has been posted or > found. I would greatly > appreciate if any one of you provides any clue to solve > this problem. > > If this is under correction for now and there is no > solution at this time > > from G03 side, is there any other program that I can > use for automatic HR > identification and calculation for thermo property > estimation? > > Many thanks in advance, > > Yangsoo Kim > > > ================================================================ > CCL:G: Hinderedrotor Problem in Gaussian03 > .. From: "Greef, T.F.A. de" > <t.f.a.d.greef]~[tue.nl> > .. Subject: CCL:G: Hinderedrotor Problem in Gaussian03 > .. Date: Tue, 6 Nov 2007 11:10:50 +0100 > > From: owner-chemistry(!)ccl.net > [mailto:owner-chemistry(!)ccl.net] > Sent: Tuesday, November 06, 2007 9:51 AM > To: Greef, T.F.A. de > Subject: CCL:G: Hinderedrotor Problem in Gaussian03 > Dear CCL members, > I am trying to use the "HF/6-31G* opt > freq=hinderedrotor" keyword in > Gaussian03 to correct the themochemical data for > contributions of internal > rotation. > It is normally terminated to calculate the hindered rotor > analysis for the > normal alkyl-chained systems. > But I met the following error messages for various > alkyl-substitutied > benzene ring systems. (e.q. toluene, ethylbenzene or > propylbenzene) > === Error Message (propylbenzene) === > Hindered Internal Rotation Analysis > Internal coordinate list checked > Check for planar centers > 1 2 3 10 360.000 > 2 1 6 7 359.984 > 3 1 4 11 360.000 > 4 3 5 12 360.000 > 5 4 6 13 360.000 > 6 2 5 14 360.000 > Check reduced barrier height. Cut-off : V/RT = 33.7561 > Check for ring deformation > Number of internal rotation degrees of freedom = 3 > NNew= 48 NTest= 3 NB= 9 IFrz= 0 IBar= 0 > ICyc= 0 > Problem with the number of degrees of freedom > Error termination... > ====================== > Does anyone have any suggestions to solve these problems? > And please tell me another softwares to calculate the > hindered rotor. > Thanks in advance. > Yangsoo Kim > ----------------------------------------------------------------------- > CCL:G: g03 Problem with "HinderedRotor" > calculations > ________________________________________ > .. From: Ulrich Scharfenort > <scharfenort]-[ltt.rwth-aachen.de> > .. Subject: CCL:G: g03 Problem with > "HinderedRotor" calculations > .. Date: Fri, 07 Mar 2008 11:22:51 +0100 > ________________________________________ > Sent to CCL by: Ulrich Scharfenort > [scharfenort=ltt.rwth-aachen.de] > Hello, > I hope maybe one of you can help me with an problem. > > Currently i try to calculate Aromatic compounds with the > HinderedRotor > option. With Alkanes HR works very fine and without any > problem so I think > it's not an problem with the coordinates. > The error-message is as follows: > Number of internal rotation degrees of freedom = 4 > NNew= 30 NTest= 4 NB= 10 IFrz= 0 IBar= 0 > ICyc= 0 > Problem with the number of degrees of freedom > > Error termination via Lnk1e in > /opt/GAUSSIAN/LINUX_amd64/g03.d02/l716.exe at > Fri Mar 7 11:10:19 2008. > Job cpu time: 0 days 0 hours 0 minutes 15.4 seconds. > > File lengths (MBytes): RWF= 17 Int= 0 D2E= 0 Chk= 10 Scr= 1 > > This was a calculation for Butylbenzene where are internal > rotations. > Does HR only work for Alkanes and nothing else? > > Maybe somebody does know for which compound classes HR > works and for which > not or and way to make it working for all compounds. > I will appreciate all the help you can provide on this > problem. > Yours sincerely > > <http://dict.leo.org/ende?lp=ende&p=eL4jU.&search=Yours>;; > Ulrich Scharfenort > > ---------------------------------------------------------------------- > CCL:G: Hindered Rotor Gaussian03 > ________________________________________ > .. From: "Tom F.A. de Greef" > <t.f.a.d.greef()tue.nl> > .. Subject: CCL:G: Hindered Rotor Gaussian03 > .. Date: Thu, 18 Jan 2007 04:38:20 -0500 > ________________________________________ > Sent to CCL by: "Tom F.A. de Greef" > [t.f.a.d.greef ~ tue.nl] > Dear all, > I want to report some deltaG values generated by a > Gaussian03 job on a > molecule > of about 20 heavy atoms (B3LYP,6_311G+(d,p). However, I > want to check if > the > assumptian that Gaussian03 makes are correct (the free > rotor assumption). I > requested a fequency job using the optimised geometry at > the > before mentioned level using these keywords: > freq=hindered rb3lyp/6-311+g(d,p) > geom=(connectivity,modredundant) > "Geometry in Cartesian coordinates" > It computes all the derivatives and computes the full > mass-weighted force > constant matrix. The calculation then starts a hindered > rotation analysis: > Internal coordinate list checked > Check for planar centers > 1 2 4 27 359.993 > 2 1 9 28 359.996 > 3 4 5 8 359.927 > 4 1 3 29 359.965 > 5 3 6 15 360.000 > 7 8 11 12 359.998 > 8 3 7 9 360.000 > 9 2 8 10 359.998 > 10 9 11 13 360.000 > 11 7 10 14 359.994 > 15 5 18 21 359.928 > 16 17 20 33 359.996 > 17 16 18 34 359.993 > 18 15 17 35 359.965 > 19 20 23 25 360.000 > 20 16 19 21 359.998 > 21 15 20 22 360.000 > 22 21 23 24 359.999 > 23 19 22 26 359.993 > Check reduced barrier height. Cut-off : V/RT = 33.7561 > Bond 3 - 5 frozen. > Estimated reduced barrier height : V/RT = > 37.5137 For a > periodicity of : 2 > Bond 5 - 15 frozen. > Estimated reduced barrier height : V/RT = > 37.5712 For a > periodicity of : 2 > Check for ring deformation > Number of internal rotation degrees of freedom = 2 > NNew= 92 NTest= 2 NB= 24 IFrz= 0 IBar= 2 > ICyc= 0 > Problem with the number of degrees of freedom > Error termination via Lnk1e in > /usr/opt/gaussian/g03/l716.exe > I know that the method used by Gaussian03 to correct for > hindered rotation > is > not always working (for example it works for butane but > fails for > methanol). For > underlying thheory: P.Y. Ayala & H.B. Schlegel, JCP > 108,2314 > Best regards, > Tom de Greef > ------------------------------------------------------------------ > CCL:G: Guassian - Hindered rotor frequency option > ________________________________________ > .. From: "Rob Noble-Eddy" > <r.noble-eddy[-]ed.ac.uk> > .. Subject: CCL:G: Guassian - Hindered rotor frequency > option > .. Date: Fri, 9 Nov 2007 09:34:04 -0500 > ________________________________________ > Sent to CCL by: "Rob Noble-Eddy" > [r.noble-eddy^-^ed.ac.uk] > Hi, > I have a molecule which contains a phenyl group, and want > to calculate the > free > energies of its two conformers. The barrier to rotation of > the phenyl group > is > around kT and so I believe any estimation of the free > energy should include > this > rotation, rather than simply using a standard frequency > calculation on the > equilibrium position. > I tried to use the freq=hinderedrotor option in gaussian > '03 to achieve > this, > but after successfully completing a geometry optimisation > it starts to do > the > frequency calculation, but stops with an error when it > tries to determine > if > there are any hindered rotors in the molecule. > I've included the output below, if anyone has any > ideas, or has used this > feature before please get in touch. > Thanks, > Rob > ============================================ > Internal coordinate list checked > Check for planar centers > 1 2 3 7 359.997 > 2 1 4 9 360.000 > 3 1 5 10 360.000 > 4 2 6 11 360.000 > 5 3 6 12 360.000 > 6 4 5 13 360.000 > Check reduced barrier height. Cut-off : V/RT = 33.7561 > Check for ring deformation > Number of internal rotation degrees of freedom = 2 > NNew= 36 NTest= 2 NB= 8 IFrz= 0 IBar= 0 > ICyc= 0 > Problem with the number of degrees of freedom > Error termination via Lnk1e in > /usr/local/Chem-Apps/g03_d01/g03/l716.exe > at Fri > Nov 9 11:29:03 2007. > > ------------------------------------------------------------ > CCL:G: How to Identify and correct for Hindered Rotors in > G03 > ________________________________________ > .. From: akef afaneh <akef_afnh(a)yahoo.com> > .. Subject: CCL:G: How to Identify and correct for Hindered > Rotors in > G03 > .. Date: Fri, 23 Nov 2007 06:37:39 -0800 (PST) > ________________________________________ > Sabry; > I do not know if I can help you to solve your problem or > not. However, I > need more information about your job to give you a suitable > example. What I > see here from the output massage is that the problem in the > constrained mode > # 2, so, the program gave you a message to redo the normal > mode analysis > with added constraints. You have also a problem in the > number of degrees of > freedom, these usually result when a certain degree of > symmetry is used and > the Gaussian recognizes another symmetry. > When we study a TS species with unrecognized bond, > Geom=Modify keyword is > usually used. > > Akef > > -------------------------------------------------------------------- > Hello CCLers, > > I'm trying to correct for hindered rotation modes using > the keyword > Freq=HinderedRotor in G03. > In fact I have no idea how to do that; I mean the > identification and the > correction. For the reactant the job terminated > successfully > but I don't know what I should get from the output. > Fot the TS, the job > failed with the following error message: > ---------------------------------------------------------------------------- > ----- > Check correspondance between vibrational and internal > rotation modes > frequencies in cm**-1 > 1 2 3 > Frequencies --- 95.0468 155.4019 177.3364 > -1474.4902 0.0101 0.0562 -0.0333 > 92.0838 -0.9973 0.4231 0.6332 > 136.3765 -0.2606 0.8307 0.3015 > 155.3244 0.4631 -0.8491 -0.9191 > 195.3921 -0.6826 0.4576 0.8660 > 343.8586 - 0.8442 0.7230 0.8824 > > ---------------------------------------------------------------------------- > One-to-one correspondance not acheived > Constrained mode 2 likely source of the problem > Bond # Atoms > 1 1 2 0.00000 > 2 2 3 0.07105 > 3 3 8 0.12548 > 4 8 9 0.74224 > Freeze coordinate 27 > Freeze coordinate 28 > Freeze coordinate 29 > Freeze coordinate 30 > Redo normal mode analysis with added constraints > Number of internal rotation degrees of freedom = 3 > NNew= 7 NTest= 3 NB= 4 IFrz= 1 IBar= 1 > ICyc= 0 > Problem with the number of degrees of freedom > Error termination via Lnk1e in C:\G03W\l716.exe at > Sat Nov 10 22:37:32 > 2007. > > ---------------------------------------------------------------------------- > ---------------------------------------------------- > > I don't understand what the message means. I shall be > very grateful if > anyone can help me (using a simple example would be fine) > Thank you in advance. > > Sabry Ahmed > > > -- > Sabry El-Taher Ahmed > Cairo University > Faculty of Science > Department of Chemistry > Cairo, Egypt. > > --------------------------------------------------------------- > > Hindered Rotor Analysis in G03 > ________________________________________ > .. From: Matthias Lein > <matthias|at|chemie.uni-marburg.de> > .. Subject: Hindered Rotor Analysis in G03 > .. Date: Mon, 28 Jun 2004 11:17:34 +0200 > ________________________________________ > Hi all, > investigating a molecule of 72 atoms I calculated the > thermodynamical > data of dissociation given by standard frequency analysis > of Gaussian98 > (and G03). > Given one rotational barrier of about 10 kcal/mol I > thought it to be > useful to try the "Freq(HinderedRotor)"-Keyword > in Gaussian to correct > the data for contributions of internal rotation. I used an > already > finished harmonic frequency analysis and the > "readfc"-keyword to avoid > recalculation of the frequencies. > The algorithm of Schlegel et al. found two internal > rotations but then > skipped the calculation with the following lines: > > Check for ring deformation > > Number of internal rotation degrees of freedom = 2 > > NNew= 156 NTest= 2 NB= 45 IFrz= 0 IBar= 7 > ICyc= 0 > > Problem with the number of degrees of freedom > > Error termination via Link716 > My questions: > 1) Does anyone know the limitations of this keyword? (No > of atoms, > degrees of freedom,...) > 2) Is there knowledge about problems and performance of > this method, > including numerical values (is it necessary or reasonable > to use these > corrections)? > Thanks in advance > Matthias. > > > > -= This is automatically added to each message by the > mailing script =- > To recover the email address of the author of the message, > please change > the strange characters on the top line to the ### sign. You > can also> Conferences: > http://server.ccl.net/chemistry/announcements/conferences/ > > Search Messages: http://www.ccl.net/htdig (login: ccl, > Password: search)