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<div>Dear vega lew:
<BR>
I see you use normal NEB method, why don't use the Climbing-Image NEB? CI-NEB will let you find the saddle-point state. And I see the path length is about 5.0 anstrong, which is a little long path that 7 images in no-CI maybe not many enough if the potential energy surface is not smooth enough. Also, increasing the spring constants k_min and k_max and decreasing the atomic masses in the input file may help some. The meanings of these parameters can be found in the original papers on Dimer and NEB methods, which can be found in the bibliography in the Q_E homepage.
<BR>
In addition, It seems I have not made you understand me in the previous email, and I meant the convergence of the electronic-structure calculations for every image can be checked only when you open the PW.out files in the directory ./tmp/**_i (i=1,2...7). The potential barrier is just the energy difference between the saddle-point state (not well difined in the no-CI method) and the initial state, so when there is something wrong with the convergence of E_ac, there must be something wrong with the energy convergence of the "saddle-point state" and the initital state, which can be modified by changing some parameters e.g. k-points numbers, smearing, nband. Or there may
<BR>
be some defects in the pseudopotential and you should better change for another one. Probably the no-CI method also can result in this kind of convergence problem due to that the structure with highest energy can not stablized during your calculations.
<BR>
One important note: the NEB is cpu time consuming, and can eaily cost over 100 iterations to converge if your parameters are not optimized, so you'd better take some tests on smaller systems to find the optimum parameters before more complicated calculations.
<BR>
May these be helpful for you!
<BR>
<BR>
Best Wishes!
<BR>
Yours Sincerely
<BR>
L.F.Huang
<BR>
<BR>
</FONT><FONT color=#444444>> My convergence of every single NEB iteration is very well. My convergence
<BR>
</FONT><FONT color=#444444>> problem is about the calculated "activation energy" (I call it as energy
<BR>
</FONT><FONT color=#444444>> barrier in last mail.), not for the energy convergence of every image.
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> here is a few lines from my output file,
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> Program PWSCF v.4.0.3 starts ...
<BR>
</FONT><FONT color=#444444>> Today is 8Oct2009 at 23:53:20
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> Parallel version (MPI)
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> Number of processors in use: 5
<BR>
</FONT><FONT color=#444444>> path-images division: nimage = 5
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> For Norm-Conserving or Ultrasoft (Vanderbilt) Pseudopotentials or PAW
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> Current dimensions of program pwscf are:
<BR>
</FONT><FONT color=#444444>> Max number of different atomic species (ntypx) = 10
<BR>
</FONT><FONT color=#444444>> Max number of k-points (npk) = 40000
<BR>
</FONT><FONT color=#444444>> Max angular momentum in pseudopotentials (lmaxx) = 3
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> gamma-point specific algorithms are used
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> initial path length = 7.8290 bohr
<BR>
</FONT><FONT color=#444444>> initial inter-image distance = 1.3048 bohr
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> calculation = neb
<BR>
</FONT><FONT color=#444444>> restart_mode = from_scratch
<BR>
</FONT><FONT color=#444444>> opt_scheme = quick-min
<BR>
</FONT><FONT color=#444444>> num_of_images = 7
<BR>
</FONT><FONT color=#444444>> nstep = 9999
<BR>
</FONT><FONT color=#444444>> CI_scheme = no-CI
<BR>
</FONT><FONT color=#444444>> first_last_opt = F
<BR>
</FONT><FONT color=#444444>> coarse-grained phase-space = F
<BR>
</FONT><FONT color=#444444>> use_freezing = F
<BR>
</FONT><FONT color=#444444>> ds = 1.0000 a.u.
<BR>
</FONT><FONT color=#444444>> k_max = 0.1000 a.u.
<BR>
</FONT><FONT color=#444444>> k_min = 0.1000 a.u.
<BR>
</FONT><FONT color=#444444>> suggested k_max = 0.6169 a.u.
<BR>
</FONT><FONT color=#444444>> suggested k_min = 0.6169 a.u.
<BR>
</FONT><FONT color=#444444>> path_thr = 0.0500 eV / A
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> ------------------------------ iteration 1
<BR>
</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = 0.2 self-consistency for image 1
<BR>
</FONT><FONT color=#444444>> cpu = 3 tcpu = 0.2 self-consistency for image 5
<BR>
</FONT><FONT color=#444444>> cpu = 4 tcpu = 0.2 self-consistency for image 6
<BR>
</FONT><FONT color=#444444>> cpu = 2 tcpu = 0.2 self-consistency for image 4
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = 0.2 self-consistency for image 7
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = 23616.8 self-consistency for image 2
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = 25603.1 self-consistency for image 3
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> activation energy (->) = 3.272591 eV
<BR>
</FONT><FONT color=#444444>> activation energy (
<BR>
</FONT><FONT color=#444444>> image energy (eV) error (eV/A) frozen
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> 1 -119085.6620746 0.024462 T
<BR>
</FONT><FONT color=#444444>> 2 -119084.9563724 2.640583 F
<BR>
</FONT><FONT color=#444444>> 3 -119083.3975295 2.385012 F
<BR>
</FONT><FONT color=#444444>> 4 -119082.3894835 2.896402 F
<BR>
</FONT><FONT color=#444444>> 5 -119083.2192599 2.998904 F
<BR>
</FONT><FONT color=#444444>> 6 -119084.7252314 2.403066 F
<BR>
</FONT><FONT color=#444444>> 7 -119085.3804446 0.025165 T
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> path length = 7.829 bohr
<BR>
</FONT><FONT color=#444444>> inter-image distance = 1.305 bohr
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> ------------------------------ iteration 2
<BR>
</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> cpu = 2 tcpu = 29648.3 self-consistency for image 4
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = 42567.1 self-consistency for image 2
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = 44477.8 self-consistency for image 3
<BR>
</FONT><FONT color=#444444>> cpu = 3 tcpu = 30626.8 self-consistency for image 5
<BR>
</FONT><FONT color=#444444>> cpu = 4 tcpu = 32197.2 self-consistency for image 6
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> activation energy (->) = 3.093816 eV
<BR>
</FONT><FONT color=#444444>> activation energy (
<BR>
</FONT><FONT color=#444444>> image energy (eV) error (eV/A) frozen
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> 1 -119085.6620746 0.024462 T
<BR>
</FONT><FONT color=#444444>> 2 -119085.0987352 2.105271 F
<BR>
</FONT><FONT color=#444444>> 3 -119083.6078363 2.170459 F
<BR>
</FONT><FONT color=#444444>> 4 -119082.5682586 2.050101 F
<BR>
</FONT><FONT color=#444444>> 5 -119083.5224117 1.596776 F
<BR>
</FONT><FONT color=#444444>> 6 -119084.8769055 1.343862 F
<BR>
</FONT><FONT color=#444444>> 7 -119085.3804446 0.025165 T
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> path length = 7.843 bohr
<BR>
</FONT><FONT color=#444444>> inter-image distance = 1.307 bohr
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>> ------------------------------ iteration 120
<BR>
</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> cpu = 2 tcpu = ******** self-consistency for image 4
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = ******** self-consistency for image 2
<BR>
</FONT><FONT color=#444444>> cpu = 3 tcpu = ******** self-consistency for image 5
<BR>
</FONT><FONT color=#444444>> cpu = 4 tcpu = ******** self-consistency for image 6
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = ******** self-consistency for image 3
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> activation energy (->) = 1.786596 eV
<BR>
</FONT><FONT color=#444444>> activation energy (
<BR>
</FONT><FONT color=#444444>> image energy (eV) error (eV/A) frozen
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> 1 -119085.6620746 0.024462 T
<BR>
</FONT><FONT color=#444444>> 2 -119085.4786718 0.223126 F
<BR>
</FONT><FONT color=#444444>> 3 -119083.9049529 0.170985 F
<BR>
</FONT><FONT color=#444444>> 4 -119083.8754787 0.076161 F
<BR>
</FONT><FONT color=#444444>> 5 -119085.1083173 0.075946 F
<BR>
</FONT><FONT color=#444444>> 6 -119085.3050720 0.015511 F
<BR>
</FONT><FONT color=#444444>> 7 -119085.3804446 0.025165 T
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> path length = 9.729 bohr
<BR>
</FONT><FONT color=#444444>> inter-image distance = 1.621 bohr
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> ------------------------------ iteration 121
<BR>
</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> cpu = 2 tcpu = ******** self-consistency for image 4
<BR>
</FONT><FONT color=#444444>> cpu = 3 tcpu = ******** self-consistency for image 5
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = ******** self-consistency for image 2
<BR>
</FONT><FONT color=#444444>> cpu = 4 tcpu = ******** self-consistency for image 6
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = ******** self-consistency for image 3
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> activation energy (->) = 1.775789 eV
<BR>
</FONT><FONT color=#444444>> activation energy (
<BR>
</FONT><FONT color=#444444>> image energy (eV) error (eV/A) frozen
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> 1 -119085.6620746 0.024462 T
<BR>
</FONT><FONT color=#444444>> 2 -119085.4781477 0.130868 F
<BR>
</FONT><FONT color=#444444>> 3 -119083.8862860 0.275250 F
<BR>
</FONT><FONT color=#444444>> 4 -119083.8905252 0.089256 F
<BR>
</FONT><FONT color=#444444>> 5 -119085.1088347 0.047586 F
<BR>
</FONT><FONT color=#444444>> 6 -119085.3051231 0.015512 F
<BR>
</FONT><FONT color=#444444>> 7 -119085.3804446 0.025165 T
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> path length = 9.725 bohr
<BR>
</FONT><FONT color=#444444>> inter-image distance = 1.621 bohr
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> ------------------------------ iteration 122
<BR>
</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> cpu = 2 tcpu = ******** self-consistency for image 4
<BR>
</FONT><FONT color=#444444>> cpu = 3 tcpu = ******** self-consistency for image 5
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = ******** self-consistency for image 2
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = ******** self-consistency for image 3
<BR>
</FONT><FONT color=#444444>> cpu = 4 tcpu = ******** self-consistency for image 6
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> activation energy (->) = 1.791716 eV
<BR>
</FONT><FONT color=#444444>> activation energy (
<BR>
</FONT><FONT color=#444444>> image energy (eV) error (eV/A) frozen
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> 1 -119085.6620746 0.024462 T
<BR>
</FONT><FONT color=#444444>> 2 -119085.4766388 0.150020 F
<BR>
</FONT><FONT color=#444444>> 3 -119083.8703582 0.360096 F
<BR>
</FONT><FONT color=#444444>> 4 -119083.9053588 0.136487 F
<BR>
</FONT><FONT color=#444444>> 5 -119085.1096015 0.054464 F
<BR>
</FONT><FONT color=#444444>> 6 -119085.3051878 0.017319 F
<BR>
</FONT><FONT color=#444444>> 7 -119085.3804446 0.025165 T
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>> ------------------------------ iteration 160
<BR>
</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> cpu = 2 tcpu = ******** self-consistency for image 4
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = ******** self-consistency for image 2
<BR>
</FONT><FONT color=#444444>> cpu = 3 tcpu = ******** self-consistency for image 5
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = ******** self-consistency for image 3
<BR>
</FONT><FONT color=#444444>> cpu = 4 tcpu = ******** self-consistency for image 6
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> activation energy (->) = 2.015566 eV
<BR>
</FONT><FONT color=#444444>> activation energy (
<BR>
</FONT><FONT color=#444444>> image energy (eV) error (eV/A) frozen
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> 1 -119085.6620746 0.024462 T
<BR>
</FONT><FONT color=#444444>> 2 -119085.4084826 0.122618 F
<BR>
</FONT><FONT color=#444444>> 3 -119083.6465085 0.151901 F
<BR>
</FONT><FONT color=#444444>> 4 -119084.1207907 0.114239 F
<BR>
</FONT><FONT color=#444444>> 5 -119085.1378794 0.024820 F
<BR>
</FONT><FONT color=#444444>> 6 -119085.3093981 0.014540 F
<BR>
</FONT><FONT color=#444444>> 7 -119085.3804446 0.025165 T
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> path length = 9.760 bohr
<BR>
</FONT><FONT color=#444444>> inter-image distance = 1.627 bohr
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> ------------------------------ iteration 161
<BR>
</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> cpu = 2 tcpu = ******** self-consistency for image 4
<BR>
</FONT><FONT color=#444444>> cpu = 3 tcpu = ******** self-consistency for image 5
<BR>
</FONT><FONT color=#444444>> cpu = 0 tcpu = ******** self-consistency for image 2
<BR>
</FONT><FONT color=#444444>> cpu = 4 tcpu = ******** self-consistency for image 6
<BR>
</FONT><FONT color=#444444>> cpu = 1 tcpu = ******** self-consistency for image 3
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> activation energy (->) = 2.019415 eV
<BR>
</FONT><FONT color=#444444>> activation energy (
<BR>
</FONT><FONT color=#444444>> image energy (eV) error (eV/A) frozen
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> 1 -119085.6620746 0.024462 T
<BR>
</FONT><FONT color=#444444>> 2 -119085.4066890 0.190727 F
<BR>
</FONT><FONT color=#444444>> 3 -119083.6426594 0.205492 F
<BR>
</FONT><FONT color=#444444>> 4 -119084.1216091 0.058992 F
<BR>
</FONT><FONT color=#444444>> 5 -119085.1383781 0.022947 F
<BR>
</FONT><FONT color=#444444>> 6 -119085.3094981 0.024415 F
<BR>
</FONT><FONT color=#444444>> 7 -119085.3804446 0.025165 T
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> path length = 9.765 bohr
<BR>
</FONT><FONT color=#444444>> inter-image distance = 1.627 bohr
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>> ......
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> as I said last mail, the activation energy goes to 1.49 eV from the intial
<BR>
</FONT><FONT color=#444444>> 2.99 eV in about 120 iterations. Then the energy barrier rise to 1.73 eV bit
<BR>
</FONT><FONT color=#444444>> by bit in following 40 iterations. And the calculation is still running
<BR>
</FONT><FONT color=#444444>> while this value is still going up.
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> How could I deal with this?
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> thank you for reading and reply
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> best,
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> vega
<BR>
</FONT><FONT color=#444444>> On Fri, Nov 6, 2009 at 4:50 PM, lfhuang wrote:
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Dear vega lew:
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Have you gone into the ./tmp directory to see the energy convergence of
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> every image? The calculational statuses of all the images can be found
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> there, and I guess your convergence problem may be due to the same reasons
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> as ordinary electronic structrue calculations, which may be modified by
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> change some parameters e.g. k-points numbers, smearing, nband. Or there may
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> be some defects in the pseudopotential and you should better change for
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> another one. May these be helpful.
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Best Wishes!
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Yours Sincerely
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> L.F.Huang
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Date: Fri, 6 Nov 2009 11:35:39 +0800
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> From: vega lew
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Subject: [Pw_forum] where is the end of an unconverged NEB calculation
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> To: PWSCF Forum
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Message-ID:
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Content-Type: text/plain; charset="iso-8859-1"
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Dear all,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> During my NEB calculations, I found there are two possible situation.
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> First,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> the calculation could be converged after about 100 iterations. Second,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> the
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> calculation never converged in more than 300 iterations. And for the
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> second
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> case, the energy barrier went down and down to a certain value, and then
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> the
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> reported energy barrier went up gradually. For example in my resent job,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> the
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> energy barrier goes to 1.49 eV from the intial 2.99 eV in about 120
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> iterations. Then the energy barrier rise to 1.73 eV bit by bit in
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> following
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> 40 iterations. And the calculation is still running while this value is
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> still going up. How could I deal with this situation? Could I take the
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> lowest value as the energy barrier of the reaction? How could I know
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> whether
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> there will be another smaller value in the longer calculation?
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> thank you for reading. Ang hints will be deeply appreciated.
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> best,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> vega
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> --
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> ==================================================================================
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Vega Lew ( weijia liu)
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Graduate student
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> State Key Laboratory of Materials-oriented Chemical Engineering
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> College of Chemistry and Chemical Engineering
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> ******************************************************************************************************************
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Email: <A href=mailto:vegalew@gmail.com>vegalew@gmail.com</A>
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Office: Room A705, Technical Innovation Building, Xinmofan Road 5#,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Nanjing,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Jiangsu, China
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> ******************************************************************************************************************
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> ------
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> ======================================================================
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> L.F.Huang(???) ph.D candidate, DFT and phonon physics
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> ======================================================================
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Add: Research Laboratory for Computational Materials Sciences,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Instutue of Solid State Physics,the Chinese Academy of Sciences,
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> P.O.Box 1129, Hefei 230031, P.R.China
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Tel: 86-551-5591464-328(office)
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Fax: 86-551-5591434
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Web: <A href=http://theory.issp.ac.cn target=_blank>http://theory.issp.ac.cn</A></FONT><FONT color=#444444>> (website of our theory group)
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> <A href=http://www.issp.ac.cn target=_blank>http://www.issp.ac.cn</A></FONT><FONT color=#444444>> (website of our institute)
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> ======================================================================
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> _______________________________________________
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> Pw_forum mailing list
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> <A href=mailto:Pw_forum@pwscf.org>Pw_forum@pwscf.org</A>
<BR>
</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> <A href=http://www.democritos.it/mailman/listinfo/pw_forum target=_blank>http://www.democritos.it/mailman/listinfo/pw_forum</A>
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>> >
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> --
<BR>
</FONT><FONT color=#444444>> ==================================================================================
<BR>
</FONT><FONT color=#444444>> Vega Lew ( weijia liu)
<BR>
</FONT><FONT color=#444444>> Graduate student
<BR>
</FONT><FONT color=#444444>> State Key Laboratory of Materials-oriented Chemical Engineering
<BR>
</FONT><FONT color=#444444>> College of Chemistry and Chemical Engineering
<BR>
</FONT><FONT color=#444444>> Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
<BR>
</FONT><FONT color=#444444>> ******************************************************************************************************************
<BR>
</FONT><FONT color=#444444>> Email: <A href=mailto:vegalew@gmail.com>vegalew@gmail.com</A>
<BR>
</FONT><FONT color=#444444>> Office: Room A705, Technical Innovation Building, Xinmofan Road 5#, Nanjing,
<BR>
</FONT><FONT color=#444444>> Jiangsu, China
<BR>
</FONT><FONT color=#444444>> ******************************************************************************************************************
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</FONT><FONT color=#444444>> ------------------------------
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> _______________________________________________
<BR>
</FONT><FONT color=#444444>> Pw_forum mailing list
<BR>
</FONT><FONT color=#444444>> <A href=mailto:Pw_forum@pwscf.org>Pw_forum@pwscf.org</A>
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</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> End of Pw_forum Digest, Vol 29, Issue 15
<BR>
</FONT><FONT color=#444444>> ****************************************
<BR>
</FONT><FONT color=#444444>>
<BR>
<BR>
<BR>
------
<BR>
======================================================================
<BR>
L.F.Huang(黄良锋) ph.D candidate, DFT and phonon physics
<BR>
======================================================================
<BR>
Add: Research Laboratory for Computational Materials Sciences,
<BR>
Instutue of Solid State Physics,the Chinese Academy of Sciences,
<BR>
P.O.Box 1129, Hefei 230031, P.R.China
<BR>
Tel: 86-551-5591464-328(office)
<BR>
Fax: 86-551-5591434
<BR>
Web: <A href=http://theory.issp.ac.cn target=_blank>http://theory.issp.ac.cn</A</FONT><FONT color=#444444>> (website of our theory group)
<BR>
<A href=http://www.issp.ac.cn target=_blank>http://www.issp.ac.cn</A</FONT><FONT color=#444444>> (website of our institute)
<BR>
======================================================================
<BR>
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