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Dear Achintya,<br>
<br>
so, you want to simulate the layer sliding in SnSe in a
phospherene-like structure.<br>
And you get a barrier height of 1.25 eV. Does this make sense? I
don't know.<br>
Maybe should ask this specific question if you want to know the
answer. Maybe<br>
you can find some published data on this kind of transition? Maybe
your<br>
colleagues can help. The input looks ok. Only suggestion I have: use
climbing<br>
image NEB which usually gives better transition states.<br>
<br>
Regards<br>
<br>
Thomas<br>
<br>
<div class="moz-cite-prefix">On 7/1/19 1:37 PM, Achintya Kumar
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAL-Kv29C56hZwkvKL3hdR5KQdjV0TxKXwt3KURoOiQZcv_mrDw@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">Dear Thomas
<div>My input and output files are attached<br>
<div>BEGIN<br>
<br>
BEGIN_PATH_INPUT<br>
&PATH<br>
restart_mode='from_scratch'<br>
string_method='neb',<br>
ds=2.D0,<br>
opt_scheme="broyden",<br>
num_of_images=15,<br>
nstep_path = 60,<br>
k_max=0.3D0,<br>
k_min=0.20D0,<br>
path_thr=0.1D0,<br>
/<br>
END_PATH_INPUT<br>
BEGIN_ENGINE_INPUT<br>
&CONTROL<br>
prefix="snse"<br>
outdir="./outdir",<br>
pseudo_dir="/cad/QE/pseudopotentials/upf_files",<br>
/<br>
&SYSTEM<br>
ibrav= 0,<br>
celldm(1)=1.889725989,<br>
nat= 4,<br>
ntyp= 2,<br>
ecutwfc= 40.0D0,<br>
ecutrho= 200.0D0,<br>
occupations= "fixed",<br>
/<br>
&ELECTRONS<br>
conv_thr = 1.D-6,<br>
mixing_beta = 0.5D0,<br>
/<br>
&IONS<br>
/<br>
ATOMIC_SPECIES<br>
Sn 118.71 Sn.pbe-dn-kjpaw_psl.0.2.UPF<br>
Se 78.960 Se.pbe-n-kjpaw_psl.0.2.UPF<br>
CELL_PARAMETERS (alat= 1.88972599)<br>
4.393133495 0.000000000 0.000000000<br>
0.000000000 4.245162285 0.000000000<br>
0.000000000 0.000000000 25.000000000<br>
<br>
K_POINTS automatic<br>
14 14 1 0 0 0<br>
BEGIN_POSITIONS<br>
FIRST_IMAGE<br>
ATOMIC_POSITIONS angstrom<br>
Sn -0.27090369 0.000000000 11.151283650<br>
Se 0.27090369 0.000000000 13.851931775<br>
Sn -2.467470438 2.122581143 13.848716350<br>
Se 2.467470438 2.122581143 11.148068225<br>
INTERMEDIATE_IMAGE<br>
ATOMIC_POSITIONS angstrom<br>
Sn 0.000000000 0.000000000 11.151283650<br>
Se 0.000000000 0.000000000 13.851931775<br>
Sn 2.196566748 2.122581143 13.848716350<br>
Se 2.196566748 2.122581143 11.148068225<br>
LAST_IMAGE<br>
ATOMIC_POSITIONS angstrom<br>
Sn 0.27090369 0.000000000 11.151283650<br>
Se -0.27090369 0.000000000 13.851931775<br>
Sn 2.467470438 2.122581143 13.848716350<br>
Se -2.467470438 2.122581143 11.148068225<br>
END_POSITIONS<br>
END_ENGINE_INPUT<br>
<br>
END<br>
</div>
</div>
<div>#############################################################</div>
<div> activation energy (->) = 1.251588 eV<br>
activation energy (<-) = 1.251588 eV<br>
<br>
image energy (eV) error (eV/A)
frozen<br>
<br>
1 -17182.1943011 0.998235 T<br>
2 -17182.4628221 0.079139 F<br>
3 -17181.6722586 0.069784 F<br>
4 -17181.2913646 0.124247 F<br>
5 -17181.0750253 0.130701 F<br>
6 -17181.2203018 0.125583 F<br>
7 -17182.2031417 0.146372 F<br>
8 -17182.0989949 0.080510 F<br>
9 -17181.3352176 0.093461 F<br>
10 -17180.9427134 0.045147 F<br>
11 -17181.0428918 0.172851 F<br>
12 -17181.6282545 0.148683 F<br>
13 -17181.7506510 0.946514 F<br>
14 -17182.4631851 0.193101 F<br>
15 -17182.1943013 0.997393 T<br>
<br>
path length = 32.289 bohr<br>
inter-image distance = 2.306 bohr<br>
<br>
---------------------------------------------------------------------------<br>
<br>
<br>
neb: reached the maximum number of steps<br>
<br>
NEB : 9h37m CPU 10h36m WALL<br>
<br>
<br>
This run was terminated on: 22:39:42 14Jun2019
<br>
<br>
=------------------------------------------------------------------------------=<br>
JOB DONE.<br>
=------------------------------------------------------------------------------=<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Mon, Jul 1, 2019 at 4:58 PM
Thomas Brumme <<a
href="mailto:thomas.brumme@uni-leipzig.de"
moz-do-not-send="true">thomas.brumme@uni-leipzig.de</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF"> Dear Achintya,<br>
<br>
without any info on how you made your NEB calculation, which
system using this or that<br>
parameter, we cannot judge if it is correct or not. If you
don't want to or can't provide these<br>
informations, then you need to discuss this with some
locals. Your supervisor?<br>
In general, if you want to know if an NEB makes sense you
need to have an idea of the<br>
potential energy surface and look at the final path...<br>
<br>
Thomas<br>
<br>
<div class="gmail-m_-4883957951565621400moz-cite-prefix">On
7/1/19 12:02 PM, Achintya Kumar wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Dear Thomas
<div>How can I make sure that my neb calculation is
correct or not.</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Mon, Jul 1, 2019 at
3:29 PM Achintya Kumar <<a
href="mailto:kumar.achintya14@gmail.com"
target="_blank" moz-do-not-send="true">kumar.achintya14@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px
0px 0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div dir="ltr">Dear Thomas
<div>I have done the same thing by splitting my path
in two separate paths, but I was just interested
to know whether it is possible or not to fix an
intermediate images.</div>
<div>Thanks for your answer. </div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Mon, Jul 1,
2019 at 1:55 PM Thomas Brumme <<a
href="mailto:thomas.brumme@uni-leipzig.de"
target="_blank" moz-do-not-send="true">thomas.brumme@uni-leipzig.de</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px
0px 0px 0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF"> Dear Achintya,<br>
<br>
I think that fixing an intermediate image is not
possible as this makes no sense.<br>
If an image is fixed, it is also an end point of
an elastic band... So, if you just<br>
split your path in two separate paths you can
fix this "intermediate" image.<br>
<br>
Cheerio<br>
<br>
Thomas<br>
<br>
<div
class="gmail-m_-4883957951565621400gmail-m_2050018332888916959gmail-m_2701065876486740373moz-cite-prefix">On
7/1/19 8:19 AM, Achintya Kumar wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Hello
<div>How can I kept frozen intermediate
images in NEB calculation? <br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr"
class="gmail-m_-4883957951565621400gmail-m_2050018332888916959gmail-m_2701065876486740373gmail_signature">
<div dir="ltr">
<div>=========================</div>
<div>Achintya Priydarshi<br>
</div>
<div>Research Scholar </div>
<div>IIT Kanpur.</div>
<div>===========================</div>
</div>
</div>
</div>
</div>
<br>
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<pre class="gmail-m_-4883957951565621400gmail-m_2050018332888916959gmail-m_2701065876486740373moz-signature" cols="72">--
Dr. rer. nat. Thomas Brumme
Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry
Leipzig University
Phillipp-Rosenthal-Strasse 31
04103 Leipzig
Tel: +49 (0)341 97 36456
email: <a class="gmail-m_-4883957951565621400gmail-m_2050018332888916959gmail-m_2701065876486740373moz-txt-link-abbreviated" href="mailto:thomas.brumme@uni-leipzig.de" target="_blank" moz-do-not-send="true">thomas.brumme@uni-leipzig.de</a>
</pre>
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-- <br>
<div dir="ltr"
class="gmail-m_-4883957951565621400gmail-m_2050018332888916959gmail_signature">
<div dir="ltr">
<div>=========================</div>
<div>Achintya Priydarshi<br>
</div>
<div>Research Scholar </div>
<div>IIT Kanpur.</div>
<div>===========================</div>
</div>
</div>
</blockquote>
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<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr"
class="gmail-m_-4883957951565621400gmail_signature">
<div dir="ltr">
<div>=========================</div>
<div>Achintya Priydarshi<br>
</div>
<div>Research Scholar </div>
<div>IIT Kanpur.</div>
<div>===========================</div>
</div>
</div>
</blockquote>
<br>
<pre class="gmail-m_-4883957951565621400moz-signature" cols="72">--
Dr. rer. nat. Thomas Brumme
Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry
Leipzig University
Phillipp-Rosenthal-Strasse 31
04103 Leipzig
Tel: +49 (0)341 97 36456
email: <a class="gmail-m_-4883957951565621400moz-txt-link-abbreviated" href="mailto:thomas.brumme@uni-leipzig.de" target="_blank" moz-do-not-send="true">thomas.brumme@uni-leipzig.de</a>
</pre>
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</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>=========================</div>
<div>Achintya Priydarshi<br>
</div>
<div>Research Scholar </div>
<div>IIT Kanpur.</div>
<div>===========================</div>
</div>
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Dr. rer. nat. Thomas Brumme
Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry
Leipzig University
Phillipp-Rosenthal-Strasse 31
04103 Leipzig
Tel: +49 (0)341 97 36456
email: <a class="moz-txt-link-abbreviated" href="mailto:thomas.brumme@uni-leipzig.de">thomas.brumme@uni-leipzig.de</a>
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