[QE-users] NEB : path length is increasing

Tue Oct 27 11:27:34 CET 2020

Dear Antoine,
Thanks for pointing out 1. I guess it's like global minimum search
(more complex, though), thus one need to either heuristically
(by chemical intuition) track some paths or make metadynamics/MC...
As for 2, with good luck (chem. int.) one may need just a few attempts,
albeit second derivative checks should confirm R, TS and P afterwards.
I believe in chem. int., as it helps to overcome both issues.
Thanks!
Regards,
  t

On Mon, Oct 26, 2020 at 9:04 PM Antoine Jay <ajay at laas.fr> wrote:
>
> Dear Omer, dear all,
> I  would like to remind that there is absolutly no reason that the path returned by the NEB is the real  MEP.
> The relaxed mep totaly depends on the initial guess of the MEP, which is most of the time a linear interpolation between the initial and final states, except if the user has some intuitive intermediate image.
>
> Regards,
>
> Antoine Jay
> LAAS CNRS
> Toulouse, France
>
>
>
> Le Lundi, Octobre 26, 2020 20:07 CET, Tamas Karpati <tkarpati at gmail.com> a écrit:
>
>
> Dear Omer,
>
> You have shown a figure of a MEP. Most probably image 4 is either R (reactant)
> or P (product). In one case im2=R, im3=TS, im4=P (and im6 is the diffused P),
> the other possibility is that im2=diffused R and im4=R then im6=P (im5=TS).
> Try to judge which is which, then use R and P to start a NEB similarly to
> your very first input that you have shared (running without a CI).
>
> As for your second question, summation of barriers is not very theoretical.
> The "bottleneck" in a multistep reaction is related the highest barrier.
> If you are able to derive an Arrhenius-like (or better) rate constant (k)
> for each step, then -for consecutive reactions- your effective k = k1*k2*...
> Derive the effective barrier if you like :)
>
> HTH,
> t
>
> On Mon, Oct 26, 2020 at 5:28 PM Omer Mutasim <omermutasim at ymail.com> wrote:
> >
> >
> > you saved my life, thanks a bunch Dr. Tamas
> >
> > I'm only interested in dissociation reaction (SO2 to SO & O) , so i should only consider image 1 & 2 only, based on AXSF file , for running NEB , right ?
> > what are these two steps you have seen ?
> >
> > i'm doing micro-kinetic modeling for reaction mechanism, so in this case , should i consider the summation of " dissociation barrier " & "diffusion barrier for dissociated SO & O to most stable sites " as the activation barrier for the elementary reaction step SO2 = SO + O ? or i should only consider the dissociation barrier ?
> >
> > Regarding AXSF, it is automatically generated by Quantum Espresso v. 6.4
> >
> >
> >
> >
> >
> >
> >
> > On Monday, October 26, 2020, 07:56:50 PM GMT+4, Tamas Karpati <tkarpati at gmail.com> wrote:
> >
> >
> > Dear Omer,
> >
> > 1, SO (being "locally" linear) is not really rotating (just nomenclature)
> > and such movements are unimportant in this case, I think
> > 2, as for the NEB: as I said, choose the beginning and end images
> > of what you consider eg. step 1 and run a NEB like before,
> > except for replacing your original 2 structures by the new duett.
> > 2b, do the same for the other elementary step to zoom-in MEP for the
> > dissociation barrier (I think I saw two steps in your MEP).
> >
> > Attaching the AXSF file was useful, thanks!
> >
> > Please let me ask a stupid question: how do you create such a useful
> > AXSF file from the NEB job's results? (Sorry for such a trivial one!!)
> >
> > Regards,
> > t
> >
> >
> > On Mon, Oct 26, 2020 at 4:20 PM Omer Mutasim <omermutasim at ymail.com> wrote:
> > >
> > >
> > > Dear Dr. Tamas
> > > your ideas are very helpful. Your are right.
> > > i have just noticed that it is a surface reaction + diffusion of dissociated products (SO & O) to most stable sites ( one reaction + 2 diffusion step). Dissociation occurs in image 2 immediately , image 3,4,5 shows diffusion of SO to most stable site (a bit far site , 3 Angstrom), (image 5 is rotation of SO), image 5 shows diffusion of "O" and again rotation of "SO" .
> > > So how to break down this steps into simpler steps than can be easily handle by NEB ?
> > > how to deal many rotations of "SO" molecule as it takes most of the images ?
> > >
> > > attached is axsf output file for the neb, please view it with xcrysden
> > > On Monday, October 26, 2020, 06:31:22 PM GMT+4, Tamas Karpati <tkarpati at gmail.com> wrote:
> > >
> > >
> > > please note that in case your preoptimized first and/or last structures
> > > are not the direct reactant and product structures but a R+diffusion
> > > or P+diffusion step results, your MEP would (and it does) look
> > > as if you have modelled a two (or even more) steps "reaction" even if
> > > just one of them is actually "chemistry".
> > >
> > > On Mon, Oct 26, 2020 at 3:11 PM Omer Mutasim <omermutasim at ymail.com> wrote:
> > > >
> > > > yes, there is a barrier for the reverse reaction.
> > > > i have check the initial & final structure again , it was relaxed until force is less than 0.003.
> > > > I do also agree with you that i should use 1 neb with barrier, and this is what i'm doing exactly.
> > > > but for this dissociation reaction step (SO2 = SO + O), i think this is the simplest elementary step i can get form SO2 molecule , it can't be broken down into a simpler elementary reaction steps.
> > > >
> > > > One this i should mention is that : for the initial structure (SO2*) , I didn't consider the most stable adsorption site for SO2* (E_ads=-0.3 eV), there is neighboring site that is a bit less stable (E_ads = -0.2 eV) which i've used for NEB. I didn't consider the former (most stable site) because the distance between molecule and surface is 3.5 A , , however for the less stable site , the distance is 1.5 A, so i thought it is not proper to consider this physisorbed state in NEB, Please correct me if i'm wrong.
> > > > thanks a lot for your help.
> > > >
> > > > Regards
> > > >
> > > > On Monday, October 26, 2020, 05:00:26 PM GMT+4, Tamas Karpati <tkarpati at gmail.com> wrote:
> > > >
> > > >
> > > > Dear Omer,
> > > >
> > > > I'd like to underline what Antoine has said and suggest that
> > > > both your first and last structures are saddle points (of order K and L,
> > > > respectively), rather than minima. Also I agree that your reaction
> > > > is not barrierless -in accordance with chemical intuition.
> > > >
> > > > To make it simple, I recommend
> > > > - make your 2nd image the first,
> > > > - make your 6th image the last,
> > > > - do use more images (even for a single step reaction,
> > > > but your MEP indicates two TS-es meaning a 2 step reaction
> > > > which -on more elaboration- may turn out to be an N step one;
> > > > only you need more points to see its real E-profile).
> > > > - rerun your NEB job.
> > > >
> > > > In fact you should check for imaginary second derivatives by the Phonon code
> > > > to ensure about each minima/maxima/TS being what they look in such a MEP.
> > > > Of course, it is painfully slow and many just skip this step.
> > > >
> > > > Other ideas:
> > > > - check the geometry of your 3 local minima and 2 TS-es
> > > > to see if they correspond to chemically rational structures.
> > > > - if they look so, decide whether the second minimum is really
> > > > your product, and if it is so then this should be your last image
> > > > (and not the 6th as I said above) for rerunning your NEB.
> > > > - of course, you can model a multistep reaction by a single NEB job,
> > > > choose the approach that best serves your postprocessing task.
> > > >
> > > > Hope this helps,
> > > > t
> > > >
> > > > On Mon, Oct 26, 2020 at 1:40 PM Antoine Jay <ajay at laas.fr> wrote:
> > > > >
> > > > > There is an energy barrier:
> > > > > the one between your intermediate minima and your final state.
> > > > > There is no barrier between initial and intermediate minima.
> > > > > You should wonder why you have an intermediate minima that is lower in energy (<0.4eV) than the final inserted molecule, this is why I was asking if it was enough relaxed.
> > > > > Maybe the first exothermic reaction gives enough energy for the second...
> > > > > But for sure, when you have such a multi-barriers reaction, a 7 images neb is not enough.
> > > > > If you need accurate results, it is better to have 1 neb per barrier, as you have 1 CI per path.
> > > > >
> > > > > Regards,
> > > > >
> > > > > Antoine Jay
> > > > > LAAS-CNRS
> > > > > Toulouse, France
> > > > >
> > > > > Le Lundi, Octobre 26, 2020 09:10 CET, Omer Mutasim <omermutasim at ymail.com> a écrit:
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Dear Dr. Jay
> > > > > I have relaxed the initial and final structures before neb.
> > > > > Regarding simulation box, i'm using sqrt(3)*sqrt(3) supercell, the other five reaction steps converged well.
> > > > > However, i have seen in the literature that similar catalyst resulted in such barrier-less dissociation.
> > > > > So my question goes like : with this oscillated MEP , can i conclude it is barrier-less reaction ? or it is even necessary for barrier-less step to have no oscillation ?
> > > > > does changing the adsorption site of the reactant (SO2) to less stable site might solve the issue ?
> > > > >
> > > > > Regards
> > > > > On Monday, October 26, 2020, 11:25:36 AM GMT+4, Antoine Jay <ajay at laas.fr> wrote:
> > > > >
> > > > >
> > > > > Dear Omer,
> > > > > I think your initial and final minima have not been well relaxed.
> > > > > When you fix the initial and final structures in a neb you must have relaxed them before, otherwise, you will have negative energy barriers.
> > > > > Moreover, you may have rotation of molecules that return local minima if your simulation box is too small.
> > > > >
> > > > > Regards,
> > > > >
> > > > > Antoine Jay
> > > > > LAAS-CNRS
> > > > > Toulouse, France
> > > > >
> > > > >
> > > > > Le Lundi, Octobre 26, 2020 06:39 CET, Omer Mutasim <omermutasim at ymail.com> a écrit:
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Thanks a lot Dr. Tamas & Dr. Jay. , it is very efficient procedure, it worked for me now for all reaction steps. cheers
> > > > >
> > > > > However for one elementary step , particularly SO2 dissociation ( SO2 = SO+O ) i got the following activation barrier, (it hasn't finished yet, but expected to remain around these values since it doesn't change much):
> > > > >
> > > > > ------------------------------ iteration 297 ------------------------------
> > > > >
> > > > > activation energy (->) = 0.000000 eV
> > > > > activation energy (<-) = 0.308512 eV
> > > > >
> > > > > image energy (eV) error (eV/A) frozen
> > > > >
> > > > > 1 -92402.4972907 0.036606 T
> > > > > 2 -92402.8008646 0.020347 F
> > > > > 3 -92402.6789202 0.048720 F
> > > > > 4 -92403.2726990 0.102631 F
> > > > > 5 -92403.0642888 0.050277 F
> > > > > 6 -92403.2377599 0.067121 F
> > > > > 7 -92402.8058032 0.029355 T
> > > > > activation energy (->) = 0.000000 eV
> > > > > activation energy (<-) = 0.308512 eV
> > > > >
> > > > >
> > > > > Attached is the MEP curve. As you see in MEP graph , there is oscillation in energies.
> > > > > is it normal to get this oscillated MEP curve for such barrier-less reaction step ? if not, how to get rid of this oscillations ?
> > > > > does using "CI" can increase this barrier a bit ?
> > > > >
> > > > > Thanks in advance
> > > > >
> > > > > Regards
> > > > > On Wednesday, October 21, 2020, 11:04:14 PM GMT+4, Omer Mutasim <omermutasim at ymail.com> wrote:
> > > > >
> > > > >
> > > > > Very helpful ideas.
> > > > > But after pre-converging with inexpensive parameters, i will get first & last image that are different than my actual images with higher parameters ( k-pointss, cutoff,..)
> > > > > So then how i can use this pre-converged path for my actual settings?
> > > > >
> > > > > Sent from Yahoo Mail for iPhone
> > > > >
> > > > >
> > > > > On Wednesday, October 21, 2020, 3:06 PM, Tamas Karpati <tkarpati at gmail.com> wrote:
> > > > >
> > > > > Dear Omar,
> > > > >
> > > > > Hope it helps, just some ideas:
> > > > > - I could tell more if you would attach the whole input file (ie. the
> > > > > structures).
> > > > > - Without knowing the structures only I can give some hints:
> > > > > -- Try using smaller PW basis and lower ecutwfc, ecutrho to speed up
> > > > > your simulation.
> > > > > -- When you obtain something more reliable result, you can change
> > > > > back to the higher basis.
> > > > > -- Try leaving opt_scheme at its default value.
> > > > > -- For such a reaction (dissociation of such a polarized molecule) you should
> > > > > expect a barrier, therefore CI_scheme should be anything except for no-CI.
> > > > > -- The best is if you can specify the CI manually in the
> > > > > CLIMBING_IMAGES section
> > > > > (choose the CI_scheme accordingly).
> > > > > Bests,
> > > > > t
> > > > >
> > > > > On Tue, Oct 20, 2020 at 6:53 PM Omer Mutasim <omermutasim at ymail.com> wrote:
> > > > > >
> > > > > > Dear All
> > > > > > I'm doning NEB for dissociation reaction of SO2 to SO +O. But it is not converging for more than a week, and the path length is increasing.
> > > > > > Please tell me what is wrong in my input file:
> > > > > >
> > > > > > below is the input & output files:
> > > > > >
> > > > > > Input file:
> > > > > >
> > > > > > BEGIN
> > > > > > BEGIN_PATH_INPUT
> > > > > > &PATH
> > > > > > restart_mode = 'restart'
> > > > > > string_method = 'neb',
> > > > > > nstep_path = 800,
> > > > > > ds = 1.D0,
> > > > > > opt_scheme = "broyden",
> > > > > > num_of_images = 7,
> > > > > > CI_scheme = 'no-CI',
> > > > > > path_thr = 0.05D0,
> > > > > >
> > > > > > /
> > > > > > END_PATH_INPUT
> > > > > > BEGIN_ENGINE_INPUT
> > > > > > &CONTROL
> > > > > > calculation = "relax"
> > > > > > prefix = 'SO2_neb'
> > > > > > outdir = './outdir'
> > > > > > pseudo_dir = '/home/yQE-test/pseudo/'
> > > > > > restart_mode = 'from_scratch'
> > > > > > forc_conv_thr = 1.0e-03
> > > > > > etot_conv_thr = 1e-04
> > > > > > nstep = 200
> > > > > > !tefield = .TRUE
> > > > > > !dipfield = .TRUE
> > > > > > /
> > > > > >
> > > > > > &SYSTEM
> > > > > > ibrav = 0
> > > > > > ecutrho = 270
> > > > > > ecutwfc = 45
> > > > > > nat = 111
> > > > > > ntyp = 4
> > > > > > occupations='smearing',smearing='gaussian',degauss=0.005
> > > > > > vdw_corr = 'DFT-D2'
> > > > > > !edir = 3 , emaxpos = 0.6808, eopreg = 0.08 , eamp = 0.001,
> > > > > > nspin = 2
> > > > > > starting_magnetization(1)= 0.01
> > > > > >
> > > > > > /
> > > > > > &ELECTRONS
> > > > > > conv_thr = 1e-06
> > > > > > electron_maxstep = 200
> > > > > > mixing_mode ='local-TF'
> > > > > > mixing_beta = 0.3
> > > > > >
> > > > > > /
> > > > > >
> > > > > > &IONS
> > > > > > /
> > > > > >
> > > > > > K_POINTS {automatic}
> > > > > > 3 3 1 0 0 1
> > > > > >
> > > > > > ATOMIC_SPECIES
> > > > > > Ni 58.69340 Ni.pbe-n-rrkjus_psl.0.1.UPF
> > > > > > P 30.97376 P.pbe-n-rrkjus_psl.1.0.0.UPF
> > > > > > S 32.065 S.pbe-n-rrkjus_psl.1.0.0.UPF
> > > > > > O 15.9999 O.pbe-n-rrkjus_psl.1.0.0.UPF
> > > > > > CELL_PARAMETERS {angstrom}
> > > > > > 11.765383541833 0.0000000000 0.0000000000
> > > > > > -5.88269177091652 10.1891210324947 0.0000000000
> > > > > > 0.0000000000 0.0000000000 30.9938690567585
> > > > > > BEGIN_POSITIONS
> > > > > > FIRST_IMAGE
> > > > > > ATOMIC_POSITIONS (angstrom)
> > > > > > S -1.181561037 6.155418563 12.124345096
> > > > > > O -1.100425541 4.672437254 11.356300976
> > > > > > O 0.190308001 6.839217965 11.448732238
> > > > > > Ni -2.738525121 4.763450297 0.239145520
> > > > > > Ni 3.139579474 1.358483744 0.232252034
> > > > > > Ni 3.135766403 8.150575392 0.235327906
> > > > > > Ni -4.673593720 8.104467836 1.780118367
> > > > > > .
> > > > > > .
> > > > > > .
> > > > > > .
> > > > > >
> > > > > > output file:
> > > > > >
> > > > > > Program NEB v.6.4.1 starts on 16Oct2020 at 11:35:32
> > > > > >
> > > > > > This program is part of the open-source Quantum ESPRESSO suite
> > > > > > for quantum simulation of materials; please cite
> > > > > > "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
> > > > > > "P. Giannozzi et al., J. Phys.:Condens. Matter 29 465901 (2017);
> > > > > > URL http://www.quantum-espresso.org",
> > > > > > in publications or presentations arising from this work. More details at
> > > > > > http://www.quantum-espresso.org/quote
> > > > > >
> > > > > > Parallel version (MPI), running on 80 processors
> > > > > >
> > > > > > MPI processes distributed on 5 nodes
> > > > > > R & G space division: proc/nbgrp/npool/nimage = 80
> > > > > >
> > > > > > parsing_file_name: input.in
> > > > > > Reading input from pw_1.in
> > > > > > Message from routine read_upf::
> > > > > >
> > > > > >
> > > > > > initial path length = 11.3145 bohr
> > > > > > initial inter-image distance = 1.8857 bohr
> > > > > >
> > > > > > string_method = neb
> > > > > > restart_mode = from_scratch
> > > > > > opt_scheme = broyden
> > > > > > num_of_images = 7
> > > > > > nstep_path = 800
> > > > > > CI_scheme = no-CI
> > > > > > first_last_opt = F
> > > > > > use_freezing = F
> > > > > > ds = 1.0000 a.u.
> > > > > > k_max = 0.1000 a.u.
> > > > > > k_min = 0.1000 a.u.
> > > > > > suggested k_max = 0.6169 a.u.
> > > > > > suggested k_min = 0.6169 a.u.
> > > > > > path_thr = 0.0500 eV / A
> > > > > >
> > > > > > ------------------------------ iteration 1 ------------------------------
> > > > > >
> > > > > > tcpu = 6.2 self-consistency for image 1
> > > > > > tcpu = 3675.5 self-consistency for image 2
> > > > > > tcpu = 7662.5 self-consistency for image 3
> > > > > > tcpu = 11422.7 self-consistency for image 4
> > > > > > tcpu = 15346.3 self-consistency for image 5
> > > > > > tcpu = 19108.7 self-consistency for image 6
> > > > > > tcpu = 22571.1 self-consistency for image 7
> > > > > >
> > > > > > activation energy (->) = 70.216194 eV
> > > > > > activation energy (<-) = 71.022062 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92468.8536637 23.505267 F
> > > > > > 3 -92442.9691259 150.213122 F
> > > > > > 4 -92406.7311409 330.353055 F
> > > > > > 5 -92431.0052901 207.333777 F
> > > > > > 6 -92469.0661237 51.663167 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 11.314 bohr
> > > > > > inter-image distance = 1.886 bohr
> > > > > >
> > > > > > ------------------------------ iteration 2 ------------------------------
> > > > > >
> > > > > > tcpu = 26119.7 self-consistency for image 2
> > > > > > tcpu = 28731.5 self-consistency for image 3
> > > > > > tcpu = 31027.4 self-consistency for image 4
> > > > > > tcpu = 34094.2 self-consistency for image 5
> > > > > > tcpu = 36988.0 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 22.531451 eV
> > > > > > activation energy (<-) = 23.337319 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92469.5101428 22.300995 F
> > > > > > 3 -92454.4158842 70.627594 F
> > > > > > 4 -92461.1206812 34.307062 F
> > > > > > 5 -92464.4669859 46.783708 F
> > > > > > 6 -92471.4896125 37.765708 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 11.384 bohr
> > > > > > inter-image distance = 1.897 bohr
> > > > > >
> > > > > > ------------------------------ iteration 3 ------------------------------
> > > > > >
> > > > > > tcpu = 39172.0 self-consistency for image 2
> > > > > > tcpu = 41888.0 self-consistency for image 3
> > > > > > tcpu = 44777.8 self-consistency for image 4
> > > > > > tcpu = 47642.0 self-consistency for image 5
> > > > > > tcpu = 50615.2 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 13.435341 eV
> > > > > > activation energy (<-) = 14.241209 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92471.6434742 16.119604 F
> > > > > > 3 -92463.5119937 28.367753 F
> > > > > > 4 -92468.1466546 16.740841 F
> > > > > > 5 -92472.7705146 11.019872 F
> > > > > > 6 -92475.3040517 10.662908 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 11.502 bohr
> > > > > > inter-image distance = 1.917 bohr
> > > > > >
> > > > > > ------------------------------ iteration 4 ------------------------------
> > > > > >
> > > > > > tcpu = 53323.8 self-consistency for image 2
> > > > > > tcpu = 56077.9 self-consistency for image 3
> > > > > > tcpu = 59014.9 self-consistency for image 4
> > > > > > tcpu = 61990.6 self-consistency for image 5
> > > > > > tcpu = 64608.8 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 6.530687 eV
> > > > > > activation energy (<-) = 7.336554 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92474.0378392 7.910468 F
> > > > > > 3 -92470.4166483 13.061889 F
> > > > > > 4 -92471.2528453 9.923078 F
> > > > > > 5 -92474.2165523 4.209611 F
> > > > > > 6 -92476.2787664 3.450159 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 11.724 bohr
> > > > > > inter-image distance = 1.954 bohr
> > > > > >
> > > > > > ------------------------------ iteration 5 ------------------------------
> > > > > >
> > > > > > tcpu = 67273.9 self-consistency for image 2
> > > > > > tcpu = 70152.2 self-consistency for image 3
> > > > > > tcpu = 73153.1 self-consistency for image 4
> > > > > > tcpu = 76203.5 self-consistency for image 5
> > > > > > tcpu = 78824.8 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 3.710859 eV
> > > > > > activation energy (<-) = 4.516727 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92475.5387437 3.615458 F
> > > > > > 3 -92473.5622985 4.695416 F
> > > > > > 4 -92473.2364760 5.734324 F
> > > > > > 5 -92474.4833513 2.877608 F
> > > > > > 6 -92476.4425910 2.876700 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 12.038 bohr
> > > > > > inter-image distance = 2.006 bohr
> > > > > >
> > > > > > ------------------------------ iteration 6 ------------------------------
> > > > > >
> > > > > > tcpu = 81355.0 self-consistency for image 2
> > > > > > tcpu = 84402.5 self-consistency for image 3
> > > > > > tcpu = 87564.5 self-consistency for image 4
> > > > > > tcpu = 90568.2 self-consistency for image 5
> > > > > > tcpu = 93110.5 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 2.560838 eV
> > > > > > activation energy (<-) = 3.366706 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.0900010 1.040106 F
> > > > > > 3 -92474.7832671 2.988289 F
> > > > > > 4 -92474.3864972 2.085630 F
> > > > > > 5 -92474.8266397 1.998808 F
> > > > > > 6 -92476.6377600 0.667994 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 12.364 bohr
> > > > > > inter-image distance = 2.061 bohr
> > > > > >
> > > > > > ------------------------------ iteration 7 ------------------------------
> > > > > >
> > > > > > tcpu = 95248.7 self-consistency for image 2
> > > > > > tcpu = 98189.3 self-consistency for image 3
> > > > > > tcpu = 101337.9 self-consistency for image 4
> > > > > > tcpu = 104423.7 self-consistency for image 5
> > > > > > tcpu = 107076.7 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 2.125802 eV
> > > > > > activation energy (<-) = 2.931670 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.0736630 1.319140 F
> > > > > > 3 -92475.4151167 1.955048 F
> > > > > > 4 -92474.8215329 1.921925 F
> > > > > > 5 -92475.0627346 2.135695 F
> > > > > > 6 -92476.7117640 0.696381 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 12.868 bohr
> > > > > > inter-image distance = 2.145 bohr
> > > > > >
> > > > > > ------------------------------ iteration 8 ------------------------------
> > > > > >
> > > > > > tcpu = 108885.3 self-consistency for image 2
> > > > > > tcpu = 111194.4 self-consistency for image 3
> > > > > > tcpu = 113961.2 self-consistency for image 4
> > > > > > tcpu = 116506.3 self-consistency for image 5
> > > > > > tcpu = 118361.2 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 2.073805 eV
> > > > > > activation energy (<-) = 2.879673 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.1622863 0.861666 F
> > > > > > 3 -92475.4162307 2.192183 F
> > > > > > 4 -92474.8735300 1.631538 F
> > > > > > 5 -92475.0684015 1.824977 F
> > > > > > 6 -92476.7113576 0.606060 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 12.633 bohr
> > > > > > inter-image distance = 2.105 bohr
> > > > > >
> > > > > >
> > > > > > .
> > > > > > .
> > > > > > .
> > > > > > .
> > > > > > .
> > > > > > .
> > > > > > reading file 'SO2_neb.path'
> > > > > >
> > > > > >
> > > > > > string_method = neb
> > > > > > restart_mode = restart
> > > > > > opt_scheme = broyden
> > > > > > num_of_images = 7
> > > > > > nstep_path = 800
> > > > > > CI_scheme = no-CI
> > > > > > first_last_opt = F
> > > > > > use_freezing = F
> > > > > > ds = 1.0000 a.u.
> > > > > > k_max = 0.1000 a.u.
> > > > > > k_min = 0.1000 a.u.
> > > > > > suggested k_max = 0.6169 a.u.
> > > > > > suggested k_min = 0.6169 a.u.
> > > > > > path_thr = 0.0500 eV / A
> > > > > >
> > > > > > ------------------------------ iteration 26 ------------------------------
> > > > > >
> > > > > > tcpu = 6.2 self-consistency for image 2
> > > > > > tcpu = 3713.3 self-consistency for image 3
> > > > > > tcpu = 7137.5 self-consistency for image 4
> > > > > > tcpu = 10796.2 self-consistency for image 5
> > > > > > tcpu = 14447.3 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 0.640765 eV
> > > > > > activation energy (<-) = 1.446632 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.3065704 0.250516 F
> > > > > > 3 -92477.0673165 0.278078 F
> > > > > > 4 -92476.7787332 0.431860 F
> > > > > > 5 -92476.4800774 0.453182 F
> > > > > > 6 -92476.5576488 0.296200 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 17.545 bohr
> > > > > > inter-image distance = 2.924 bohr
> > > > > >
> > > > > > ------------------------------ iteration 27 ------------------------------
> > > > > >
> > > > > > tcpu = 18237.5 self-consistency for image 2
> > > > > > tcpu = 20736.0 self-consistency for image 3
> > > > > > tcpu = 23008.1 self-consistency for image 4
> > > > > > tcpu = 25721.8 self-consistency for image 5
> > > > > > tcpu = 28310.3 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 0.643277 eV
> > > > > > activation energy (<-) = 1.449145 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.3040583 0.235899 F
> > > > > > 3 -92477.0080434 0.474599 F
> > > > > > 4 -92476.8143156 0.678632 F
> > > > > > 5 -92476.4592005 0.597470 F
> > > > > > 6 -92476.4827638 0.224064 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 18.367 bohr
> > > > > > inter-image distance = 3.061 bohr
> > > > > >
> > > > > > ------------------------------ iteration 28 ------------------------------
> > > > > >
> > > > > > tcpu = 30382.0 self-consistency for image 2
> > > > > > tcpu = 32498.8 self-consistency for image 3
> > > > > > tcpu = 34597.5 self-consistency for image 4
> > > > > > tcpu = 37250.7 self-consistency for image 5
> > > > > > tcpu = 39649.7 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 0.651733 eV
> > > > > > activation energy (<-) = 1.457601 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.2956021 0.236096 F
> > > > > > 3 -92476.9388664 0.680956 F
> > > > > > 4 -92476.8025379 0.874373 F
> > > > > > 5 -92476.3933083 0.734403 F
> > > > > > 6 -92476.4272820 0.239132 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 19.115 bohr
> > > > > > inter-image distance = 3.186 bohr
> > > > > >
> > > > > > ------------------------------ iteration 29 ------------------------------
> > > > > >
> > > > > > tcpu = 41622.7 self-consistency for image 2
> > > > > > tcpu = 43787.2 self-consistency for image 3
> > > > > > tcpu = 45892.1 self-consistency for image 4
> > > > > > tcpu = 48482.6 self-consistency for image 5
> > > > > > tcpu = 50617.1 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 0.661553 eV
> > > > > > activation energy (<-) = 1.467420 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.2857825 0.249692 F
> > > > > > 3 -92476.8823826 0.778237 F
> > > > > > 4 -92476.7843580 1.002202 F
> > > > > > 5 -92476.3323697 0.748960 F
> > > > > > 6 -92476.3885082 0.238984 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 19.742 bohr
> > > > > > inter-image distance = 3.290 bohr
> > > > > >
> > > > > > ------------------------------ iteration 30 ------------------------------
> > > > > >
> > > > > > tcpu = 52474.3 self-consistency for image 2
> > > > > > tcpu = 54679.9 self-consistency for image 3
> > > > > > tcpu = 57012.5 self-consistency for image 4
> > > > > > tcpu = 59877.3 self-consistency for image 5
> > > > > > tcpu = 62490.2 self-consistency for image 6
> > > > > >
> > > > > > activation energy (->) = 0.704760 eV
> > > > > > activation energy (<-) = 1.510628 eV
> > > > > >
> > > > > > image energy (eV) error (eV/A) frozen
> > > > > >
> > > > > > 1 -92476.9473351 0.023792 T
> > > > > > 2 -92476.2668397 0.342411 F
> > > > > > 3 -92476.7810889 0.907920 F
> > > > > > 4 -92476.7414553 1.153276 F
> > > > > > 5 -92476.2425749 0.898295 F
> > > > > > 6 -92476.3370447 0.341313 F
> > > > > > 7 -92477.7532028 0.024858 T
> > > > > >
> > > > > > path length = 20.745 bohr
> > > > > > inter-image distance = 3.457 bohr
> > > > > >
> > > > > > ------------------------------ iteration 31 ------------------------------
> > > > > >
> > > > > > tcpu = 64431.3 self-consistency for image 2
> > > > > > tcpu = 66430.0 self-consistency for image 3
> > > > > > tcpu = 68491.4 self-consistency for image 4
> > > > > > tcpu = 70987.8 self-consistency for image 5
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > > > > > users mailing list users at lists.quantum-espresso.org
> > > > > > https://lists.quantum-espresso.org/mailman/listinfo/users
> > > > > _______________________________________________
> > > > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > > > > users mailing list users at lists.quantum-espresso.org
> > > > > https://lists.quantum-espresso.org/mailman/listinfo/users
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > > > > users mailing list users at lists.quantum-espresso.org
> > > > > https://lists.quantum-espresso.org/mailman/listinfo/users
> > > > >
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > > > > users mailing list users at lists.quantum-espresso.org
> > > > > https://lists.quantum-espresso.org/mailman/listinfo/users
> > > > _______________________________________________
> > > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > > > users mailing list users at lists.quantum-espresso.org
> > > > https://lists.quantum-espresso.org/mailman/listinfo/users
> > > > _______________________________________________
> > > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > > > users mailing list users at lists.quantum-espresso.org
> > > > https://lists.quantum-espresso.org/mailman/listinfo/users
> > > _______________________________________________
> > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > > users mailing list users at lists.quantum-espresso.org
> > > https://lists.quantum-espresso.org/mailman/listinfo/users
>
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
>
>
>
>
>
>   _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users