From owner-chemistry@ccl.net Tue Feb 19 02:13:00 2013 From: "sobereva sobjubao++yahoo.com.cn" To: CCL Subject: CCL:G: problem with NLMO-NBO calculations. Message-Id: <-48258-130219005702-4928-FEyjc+/TggjDV3qDFEtT0Q#,#server.ccl.net> X-Original-From: sobereva Content-Type: multipart/alternative; boundary="-381987588-385742916-1361253410=:78705" Date: Tue, 19 Feb 2013 13:56:50 +0800 (CST) MIME-Version: 1.0 Sent to CCL by: sobereva [sobjubao#,#yahoo.com.cn] ---381987588-385742916-1361253410=:78705 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello, =A0 This is a well-known limitation of NLMO analysis in NBO 3.1, which is embed= ded in Gaussian as L607 module. To address this problem, you should inspect= occupation number of each NBO, and try to alter the atom sequence in Gauss= ian input file so that the NBO with the highest occupation number could be = present at the beginning of the NBO list. =A0 This limitation is not existed in later versions of NBO, e.g. NBO 5.0, unfo= rtunately they are not free of charge. =A0 Best wishes, =A0 Tian Lu --- On Mon, 2/18/13, Bijan Mondal mondal.bijan[*]gmail.com wrote: > From: Bijan Mondal mondal.bijan[*]gmail.com Subject: CCL: problem with NLMO-NBO calculations. To: "Lu, Tian " Date: Monday, February 18, 2013, 2:18 PM Dear Users, I want to calculate bond multiplicity of the compound of my interest. I incorporated pop=3DNBOread in the route section and putted the following = lines after mentioning the basis set. $nbo bndidx nlmo $end I used BP86/def2-SVP basis set. My system contains Ru, C, B, H, O elements = and I applied effective core potential on Ru atom with the keyword guess=3D= read. But I am unable to see the result and my calculations ended up with the fol= lowing lines. =A0NATURAL LOCALIZED MOLECULAR ORBITAL (NLMO) ANALYSIS: =A0Highest occupied NBOs are not at the beginning of the NBO list; =A0The NLMO program is not currently set up to handle this. Could you please tell me what is the problem and how to solve it? Thank you very much. With best regards, Bijan --=20 "There are no such electron-deficient compounds, =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =A0only theory-deficient chemists." -- R.= E. Rundle =A0 Bijan Mondal Research Scholar Mob: 7667156593 Department of Chemistry I.I.T Madras Chennai ---381987588-385742916-1361253410=:78705 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable ---381987588-385742916-1361253410=:78705-- From owner-chemistry@ccl.net Tue Feb 19 03:01:00 2013 From: "Benoit Benoit bonoit_10#,#yahoo.fr" To: CCL Subject: CCL: Epoxyde Message-Id: <-48259-130219030031-31367-bARjbiva4s67q5T1eBU1EA!A!server.ccl.net> X-Original-From: "Benoit Benoit" Date: Tue, 19 Feb 2013 03:00:30 -0500 Sent to CCL by: "Benoit Benoit" [bonoit_10===yahoo.fr] Dear CCLers, I'm writing to enquire about something related to the the formation of epoxydes. Let's be a biradical intermediate that leads to an epoxyde, so in this case this formation (passage from the biradical to the epoxyde) does it need a transition state or not? Any help and suggestions are really appreciated Sincerely, Benoit From owner-chemistry@ccl.net Tue Feb 19 08:32:00 2013 From: "sobereva sobjubao-#-yahoo.com.cn" To: CCL Subject: CCL:G: EDA-ELF calculations. Message-Id: <-48260-130219031623-10798-THBSUOPpZihnbuOFZ6lIUQ]![server.ccl.net> X-Original-From: sobereva Content-Type: multipart/alternative; boundary="-404248122-1900165247-1361261770=:52106" Date: Tue, 19 Feb 2013 16:16:10 +0800 (CST) MIME-Version: 1.0 Sent to CCL by: sobereva [sobjubao!^!yahoo.com.cn] ---404248122-1900165247-1361261770=:52106 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello, =A0 1 You can use IOp(6/80=3D1) keyword to print Mayer bond order, or use "bndi= dx" keyword in NBO 3.1 program (as you mentioned in another post on CCL) to= obtain Wiberg bond order in natural atomic orbital basis (if NLMO keyword = is also specified, NLMO bond order will be printed together). Besides, if y= ou want to gain deeper insight on bond order or want to calculate other typ= es of bond order, you can use Multiwfn program (http://multiwfn.codeplex.co= m). By using .fch file as input, aside from Mayer bond order, you can also = obtain multi-center bond order, Mulliken bond order (can be decomposed to M= O contribution), orbital occupancy-perturbed Mayer bond order (see JCTC,8,9= 08), Wiberg bond order in Lowdin basis, fuzzy bond order (see JPCA,109,9904= ) and Laplacian bond order. =A0 2 In general EDA analysis is used to decompose interaction energy into phys= ical components, such as electrostatic term, exchange-repulsion term, polar= ization term, etc. Gaussian itself doesn't support EDA. To perform EDA anal= ysis you can use such as GAMESS-US, Q-Chem and ADF program. =A0 3 You can use Multiwfn program to draw curve map, plane map (including cont= our map, color-filled map, relief map, vector field map, etc.) or isosurfac= e map for ELF. The operation is quite easy and the calculation speed is rat= her fast, please consult the related examples given in Section 4.3, 4.4 and= 4.5 of the program manual. The required input file (.wfn or .wfx or .fch) = can be directly produced by G09. In addition, topology analysis of ELF is a= lso supported and can be directly visualized in Multiwfn, see Section 4.2 f= or example. Note that in some examples what is discussed is LOL (localized = orbital locator) rather than ELF, in fact LOL and ELF are very similar, and= the operation steps=A0are completely exchangeable. PS: In the upcoming release (version 3.0) of this program, integration of E= LF basin will be available, thus such as average electron population and mu= ltipole moments in ELF basins will be able to be calculated. =A0 Best wishes, =A0 Tian Lu School of Chemical and Biological Engineering University of Science and Technology Beijing No.30, XueYuan road, HaiDian district, Beijing, P. R. China --- On Mon, 2/18/13, Bijan Mondal mondal.bijan a gmail.com wrote: > From: Bijan Mondal mondal.bijan a gmail.com Subject: CCL:G: EDA-ELF calculations. To: "Lu, Tian " Date: Monday, February 18, 2013, 2:17 PM Dear Users, =A0=A0 I need couple of suggestions regarding my DFT calculations as I am v= ery new in this area. 1. How can I calculate bond order/multiplicity of any compound? How can I e= xtract the DATA from my output file. 2. What is the EDA analysis and how does it helps us? How to set an EDA cal= culations and which portion of my output I have to look at? 3. How to do ELF calculations and how to visualize them? I have access to Gaussian09 only. Could you please help me by answering my quarries.=A0 I appreciate your hel= p. Thank you in advance. With best regards, Bijan --=20 "There are no such electron-deficient compounds, =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =A0only theory-deficient chemists." -- R.= E. Rundle =A0 Bijan Mondal Research Scholar Mob: 7667156593 Department of Chemistry I.I.T Madras Chennai ---404248122-1900165247-1361261770=:52106 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hello,
 
This is a well-known limitation of NLMO analysis in NBO 3.1, which is = embedded in Gaussian as L607 module. To address this problem, you should in= spect occupation number of each NBO, and try to alter the atom sequence in = Gaussian input file so that the NBO with the highest occupation number coul= d be present at the beginning of the NBO list.
 
This limitation is not existed in later versions of NBO, e.g. NBO 5.0,= unfortunately they are not free of charge.
 
Best wishes,
 
Tian Lu


--- On Mon, 2/18/13, Bijan Mondal mondal.bijan[*]gmail.com = <owner-chemistry:ccl.net> wrote:

From: Bijan Mondal mondal.bijan[*]gmail.com <o= wner-chemistry:ccl.net>
Subject: CCL: problem with NLMO-NBO calculati= ons.
To: "Lu, Tian " <sobjubao:yahoo.com.cn>
Date: Mond= ay, February 18, 2013, 2:18 PM

Dear Users,

I want to calculate b= ond multiplicity of the compound of my interest.
I incorporated pop=3DNB= Oread in the route section and putted the following lines after mentioning = the basis set.
$nbo bndidx nlmo $end
I used BP86/def2-SVP basis set. = My system contains Ru, C, B, H, O elements and I applied effective core pot= ential on Ru atom with the keyword guess=3D= read.

But I am unable to see the result and my calcula= tions ended up with the following lines.

 NATURAL LOCALIZED MOL= ECULAR ORBITAL (NLMO) ANALYSIS:

 Highest occupied NBOs are not = at the beginning of the NBO list;
 The NLMO program is not currentl= y set up to handle this.

Could you please tell me what is the proble= m and how to solve it?

Thank you very much.
With best regards,
Bijan

--
"There are no such electron-deficient compounds,=
 &nbs= p;           only theory-deficie= nt chemists." -- R.E. Rundle
<= FONT size=3D+0>
 
Bijan Mondal
Research Scholar
Mob: 7667156593
Department of Chemistry
I.I.T Ma= dras
Chennai
---404248122-1900165247-1361261770=:52106-- From owner-chemistry@ccl.net Tue Feb 19 09:06:00 2013 From: "Benoit Benoit bonoit_10**yahoo.fr" To: CCL Subject: CCL: Negative activation energy/non Arrhenius Message-Id: <-48261-130219083505-8493-Hi1Otpig7SC3u2MpzY/L3Q:_:server.ccl.net> X-Original-From: "Benoit Benoit" Date: Tue, 19 Feb 2013 08:35:01 -0500 Sent to CCL by: "Benoit Benoit" [bonoit_10_+_yahoo.fr] Dear CCLers, I'd like to enquire about negative activation energies that some reactions can have, what's the meaning of such negative value? Does is mean that the reaction is barrierless? Any help is appreciated Best regards Benoit From owner-chemistry@ccl.net Tue Feb 19 10:54:00 2013 From: "Alan Shusterman alan[A]reed.edu" To: CCL Subject: CCL: Epoxyde Message-Id: <-48262-130219105205-23949-TCbATQXp7LPsZYB7ZF7MUg,+,server.ccl.net> X-Original-From: Alan Shusterman Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Date: Tue, 19 Feb 2013 07:51:55 -0800 MIME-Version: 1.0 Sent to CCL by: Alan Shusterman [alan=reed.edu] Interesting question. Back in the early 70's there was a lot of computational and experimental work on ring-closing of trimethylene diradical (all-carbon version of your diradical). The thought was: ring-strain might introduce a barrier to radical recombination. I believe epoxides were also considered back then. You could look for work by Doering, Berson, Bergman, and Hoffmann (sorry, I don't have any references handy). Alan On 2/19/2013 12:00 AM, Benoit Benoit bonoit_10#,#yahoo.fr wrote: > Sent to CCL by: "Benoit Benoit" [bonoit_10===yahoo.fr] > Dear CCLers, > > I'm writing to enquire about something related to the the formation of epoxydes. > Let's be a biradical intermediate that leads to an epoxyde, so in this case this formation (passage from the biradical to the epoxyde) does it need a transition state or not? > > Any help and suggestions are really appreciated > > Sincerely, > > Benoit> > > -- Alan Shusterman Chemistry Department Reed College Portland, OR 97202-8199 503-517-7699 http://blogs.reed.edu/alan/ "Nature doesn't make long speeches." Lao Tzu 23 From owner-chemistry@ccl.net Tue Feb 19 11:28:00 2013 From: "Emilio Gallicchio emilio__biomaps.rutgers.edu" To: CCL Subject: CCL: Negative activation energy/non Arrhenius Message-Id: <-48263-130219110402-28440-q2PtODUJTBc3kFqxRzvG2Q{}server.ccl.net> X-Original-From: Emilio Gallicchio Content-Type: text/plain; charset=ISO-8859-1 Date: Tue, 19 Feb 2013 11:03:53 -0500 MIME-Version: 1.0 Sent to CCL by: Emilio Gallicchio [emilio[*]biomaps.rutgers.edu] > > I'd like to enquire about negative activation energies that some reactions can have, what's the meaning of such negative value? It usually refers to a case in which the rate of the reaction slows down with increasing temperature, as for example for protein folding above a certain temperature (see for example http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2000486/ , the section on "Thermodynamic Model for Anti-Arrhenius Behavior".) > Does is mean that the reaction is barrierless? No, otherwise the kinetics of the system could not be described by a reaction rate. I think it signifies that the (free energy) barrier is due to an entropic bottleneck rather than to an energy barrier. Emilio -- Emilio Gallicchio Dept. of Chemistry & Chemical Biology Rutgers University WWW: http://hpcp.rutgers.edu/~emilio From owner-chemistry@ccl.net Tue Feb 19 15:30:00 2013 From: "Pieremanuele Canepa canepap#%#wfu.edu" To: CCL Subject: CCL:G: cubegen utility in Gaussian Message-Id: <-48264-130219152924-7030-yde+LqUW4EARJUR++3r4yg-#-server.ccl.net> X-Original-From: Pieremanuele Canepa Content-Type: multipart/alternative; boundary="Apple-Mail=_A0C532E3-A8B4-4DEF-875F-5BE72A5E2C1A" Date: Tue, 19 Feb 2013 15:29:15 -0500 Mime-Version: 1.0 (Apple Message framework v1283) Sent to CCL by: Pieremanuele Canepa [canepap[]wfu.edu] --Apple-Mail=_A0C532E3-A8B4-4DEF-875F-5BE72A5E2C1A Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Dear All,=20 is there a way to force cubegen to spit a cube file that looks like a = cube, rather than a rectangle? =20 I read the page http://www.gaussian.com/g_tech/g_ur/u_cubegen.htm at = the point attached below.=20 However I don't understand what x0, y0 and Z0 really represent. Do these = coordinate represent the=20 the origin of the rectangle lattice? is not clear what these numbers = are.=20 A value of -1 says to read the cube specification from the input stream, = according to the following format: IFlag, X0, Y0, Z0 Output unit number and initial = point. N1, X1, Y1, Z1 Number of points and step-size in the = X-direction. N2, X2, Y2, Z2 Number of points and step-size in the = Y-direction. N3, X3, Y3, Z3 Number of points and step-size in the = Z-direction. IFlag is the output unit number. If IFlag is less than 0, then a = formatted file will be produced; otherwise, an unformatted file will be = written.=20 If N1<0 the input cube coordinates are assumed to be in Bohr, otherwise, = they are interpreted as Angstroms. |N1| is used as the number of = X-direction points in any case; N2 and N3 specify the number of points = in the Y and Z directions, respectively. Note that the three axes are = used exactly as specified; they are not orthogonalized, so the grid need = not be rectangular.=20 The value -5 says to read in an arbitrary list of points from standard = input. If you enter this input by hand, terminate the input with an = end-of-file (i.e., Ctrl-D under Unix). Alternatively, you can redirect = standard input to a file containing the list of points (do not place a = blank line or Ctrl-D at the end of the file). Thanks, Piero=20 _____________________________________ Pieremanuele (Piero) Canepa PhD =20 Wake Forest University, Department of Physics Winston-Salem, NC 27109 (USA) =20 t: + 001 (336) 758 4222 c: +001 (336) 602 6045 f: + 001 (336) 758 6142 skype: pieremanuele _____________________________________ --Apple-Mail=_A0C532E3-A8B4-4DEF-875F-5BE72A5E2C1A Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Dear = All, 

is there a way to force cubegen to spit a = cube file that looks like a cube, rather than a rectangle? =  

I read the page  http://www.gaus= sian.com/g_tech/g_ur/u_cubegen.htm  at the point attached = below. 
However I don't understand what x0, y0 and Z0 = really represent. Do these coordinate represent the 
the = origin of the rectangle lattice? is not clear what these numbers = are. 

A value of -1 says to read the cube specification = > from the input stream, according to the following format:

Hello,
 
1 You can use IOp(6/80=3D1) keyword to print Mayer bond order, or use = "bndidx" keyword in NBO 3.1 program (as you mentioned in another post on CC= L) to obtain Wiberg bond order in natural atomic orbital basis (if NLMO key= word is also specified, NLMO bond order will be printed together). Besides,= if you want to gain deeper insight on bond order or want to calculate othe= r types of bond order, you can use Multiwfn program (http://multiwfn.codeplex.com). By using .fch file as= input, aside from Mayer bond order, you can also obtain multi-center bond = order, Mulliken bond order (can be decomposed to MO contribution), orbital = occupancy-perturbed Mayer bond order (see JCTC,8,908), Wiberg bond order in= Lowdin basis, fuzzy bond order (see JPCA,109,9904) and Laplacian bond orde= r.
 
2 In general EDA analysis is used to decompose interaction energy into= physical components, such as electrostatic term, exchange-repulsion term, = polarization term, etc. Gaussian itself doesn't support EDA. To perform EDA= analysis you can use such as GAMESS-US, Q-Chem and ADF program.
 
3 You can use Multiwfn program to draw curve map, plane map (including= contour map, color-filled map, relief map, vector field map, etc.) or isos= urface map for ELF. The operation is quite easy and the calculation speed i= s rather fast, please consult the related examples given in Section 4.3, 4.= 4 and 4.5 of the program manual. The required input file (.wfn or .wfx or .= fch) can be directly produced by G09. In addition, topology analysis of ELF= is also supported and can be directly visualized in Multiwfn, see Section = 4.2 for example. Note that in some examples what is discussed is LOL (local= ized orbital locator) rather than ELF, in fact LOL and ELF are very similar= , and the operation steps are completely exchangeable.
PS: In the u= pcoming release (version 3.0) of this program, integration of ELF basin wil= l be available, thus such as average electron population and multipole mome= nts in ELF basins will be able to be calculated.
 
Best wishes,
 
Tian Lu

School of Chemical and Biological Engineering
University of Sci= ence and Technology Beijing
No.30, XueYuan road, HaiDian district, Beiji= ng, P. R. China

--- On Mon, 2/18/13, Bijan Mondal mondal.bijan a = gmail.com <owner-chemistry**ccl.net> wrote:

From: Bijan Mondal mondal.bijan a gmail.com <o= wner-chemistry**ccl.net>
Subject: CCL:G: EDA-ELF calculations.
To: = "Lu, Tian " <sobjubao**yahoo.com.cn>
Date: Monday, February= 18, 2013, 2:17 PM

Dear Users,

   I need couple of suggestions r= egarding my DFT calculations as I am very new in this area.

1. How c= an I calculate bond order/multiplicity of any compound? How can I extract t= he DATA from my output file.
2. What is the EDA analysis and how does it= helps us? How to set an EDA calculations and which portion of my output I = have to look at?
3. How to do ELF calculations and how to visualize them= ?

I have access to Gaussian09 only.

Cou= ld you please help me by answering my quarries.  I appreciate your hel= p.

Thank you in advance.
With best regards,
Bijan


--
"There are no such electron-deficient compounds,=
 &nbs= p;           only theory-deficie= nt chemists." -- R.E. Rundle
<= FONT size=3D+0>
 
Bijan Mondal
Research Scholar
Mob: 7667156593
Department of Chemistry
I.I.T Ma= dras
Chennai
IFlag, = X0, Y0, Z0        Output unit number and initial = point.
N1, X1, Y1, Z1Number of points and step-size in the = X-direction.
N2, X2, Y2, Z2Number of points and step-size in the = Y-direction.
N3, X3, Y3, Z3Number of points and step-size in the = Z-direction.
 is the output unit number. If  is less than 0, then a formatted file will be produced; = otherwise, an unformatted file will be written. 

If N<0 the input cube coordinates are assumed to be in Bohr, = otherwise, they are interpreted as Angstroms. |1| is used as the number of = X-direction points in any case; 2 and 3 specify the number of = points in the Y and Z directions, respectively. Note that the three axes = are used exactly as specified; they are not orthogonalized, so the grid = need not be rectangular. 
The value -5 says to read in an = arbitrary list of points from standard input. If you enter this input by = hand, terminate the input with an end-of-file (i.e., Ctrl-D under Unix). = Alternatively, you can redirect standard input to a file containing the = list of points (do not place a blank line or Ctrl-D at the end of the = file).


Thanks, = Piero 
To: CCL Subject: CCL: Epoxyde Message-Id: <-48265-130219165839-14739-t6uL18gDnaAK1vLV1zruCQ#%#server.ccl.net> X-Original-From: "Ramon Crehuet" Date: Tue, 19 Feb 2013 16:58:38 -0500 Sent to CCL by: "Ramon Crehuet" [rcsqtc|a|iqac.csic.es] Dear Benoit, I would bet there is a transition state. You might need multi-reference methods to correctly describe the biradical and the closed shell species. The reaction mechanism from carbonyl oxide H2COO to dioxyrane is electronically pretty complex, and the system is isoelectronic to en epoxyde. But if the TS does not exist, then you shouldn't speak of a biradical intermediate. Without a transition state there can't be an intermediate, only certain structures of the reaction path which have a biradical character. This is also relevant to experimentalists. A structure that is not a free energy minimum doesn't have a well-defined population and cannot be detected as such. Hope this helps, Ramon From owner-chemistry@ccl.net Tue Feb 19 20:56:01 2013 From: "Amy Austin amy_jean_austin*yahoo.com" To: CCL Subject: CCL: Negative activation energy/non Arrhenius Message-Id: <-48266-130219205435-23678-xgckZ2hr9Lhtwmlv9HKTMg[-]server.ccl.net> X-Original-From: Amy Austin Content-Type: multipart/alternative; boundary="752418115-821153590-1361325269=:61634" Date: Tue, 19 Feb 2013 17:54:29 -0800 (PST) MIME-Version: 1.0 Sent to CCL by: Amy Austin [amy_jean_austin---yahoo.com] --752418115-821153590-1361325269=:61634 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello Benoit,=0A=0AIt sounds like you have missed at least one low energy i= ntermediate along the path. You could tie everything together with some IRC= 's after you've identified the relevant transition states.=0A=0ABest,=A0 = =0A=0AAmy=0A=0A=0A=0A=0A________________________________=0A From: Benoit Be= noit bonoit_10**yahoo.fr =0ATo: "Austin, Amy J -id= #4i6-" =0ASent: Tuesday, February 19, 2013 8:35= AM=0ASubject: CCL: Negative activation energy/non Arrhenius=0A =0A=0ASent = to CCL by: "Benoit=A0 Benoit" [bonoit_10_+_yahoo.fr]=0ADear CCLers,=0A=0AI'= d like to enquire about negative activation energies that some reactions ca= n have, what's the meaning of such negative value?=0ADoes is mean that the = reaction is barrierless?=0A=0AAny help is appreciated=0A=0ABest regards=0A= =0ABenoit=0A=0A=0A=0A-=3D This is automatically added to each message by th= e mailing script =3D-=0ATo recover the email address of the author of the m= essage, please change=0Athe strange characters on the top line to the :: sig= n. You can also=0A=0A= =0A=0A=A0 =A0 =A0 http://ww= w.ccl.net/cgi-bin/ccl/send_ccl_message=0A=0AE-mail to administrators: CHEMI= STRY-REQUEST::ccl.net or use=0A=A0 =A0 =A0 http://www.ccl.net/cgi-bin/ccl/se= nd_ccl_message=0A=0A=0A=A0 =A0 =A0 http://www.ccl.ne= t/chemistry/sub_unsub.shtml=0A=0ABefore posting, check wait time at: http:/= /www.ccl.net=0A=0A=0AConferences: http://serve= r.ccl.net/chemistry/announcements/conferences/=0A=0ASearch Messages: http:/= /www.ccl.net/chemistry/searchccl/index.shtml=0A=0AIf your mail bounces from= CCL with 5.7.1 error, check:=0A=A0 =A0 =A0= =0A=0A--752418115-821153590-1361325269=:61634 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hello Benoit,

It sounds l= ike you have missed at least one low energy intermediate along the path. Yo= u could tie everything together with some IRC's after you've identified the= relevant transition states.

Best, 

Amy
<= br>

From: Benoit Benoit bonoit_10**yahoo.fr <owner-chemistry::cc= l.net>
To: "Austin,= Amy J " <amy_jean_austin::yahoo.com>
Sent: Tuesday, February 19, 2013 8:35 AM
= Subject: CCL: Negative activation = energy/non Arrhenius

=0A
Sent to CCL by: "Benoit&= nbsp; Benoit" [bonoit_10_+_yahoo.fr]
Dear CCLers,

I'd like to enq= uire about negative activation energies that some reactions can have, what'= s the meaning of such negative value?
Does is mean that the reaction is = barrierless?

Any help is appreciated

Best regards

Beno= it



-=3D This is automatically added to each message by the m= ailing script =3D-
To recover the email address of the author of the mes= sage, please change
the strange characters on the top line to the :: sign= . You can also=
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Before posting, check wait time at= : http://www.ccl.net
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Search Mes= sages: http://www.ccl.net/chemistry/searchccl/index.shtml

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