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Hi,<br>
<br>
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Is there any way to initialize spring constants based on the type of material I am using?<br>
<br>
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Soumyajit<br>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> users <users-bounces@lists.quantum-espresso.org> on behalf of Tone Kokalj <tone.kokalj@ijs.si><br>
<b>Sent:</b> Thursday, October 10, 2019 12:59:16 AM<br>
<b>To:</b> users@lists.quantum-espresso.org <users@lists.quantum-espresso.org><br>
<b>Subject:</b> Re: [QE-users] Regarding initialization of elastic constants for NEB code</font>
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<div class="PlainText">On Thu, 2019-10-10 at 00:21 +0000, Jana, Soumyajit wrote:<br>
> Hi,<br>
> <br>
> I am using NEB code to calculate vacancy jump activation energy in<br>
> pure copper. I am not sure how to initialize elastic constants (<br>
> k_max and k_min)<br>
<br>
Here is a simple empirical recommendation based on my experience: do<br>
not initialize them, but rely on default values - they are OK for most<br>
purposes (K_max and k_min are not really that crucial). But if you want<br>
to initialize them nevertheless, then your k_max is OK, but k_min<br>
appears too tiny, use something like 0.1 instead.<br>
<br>
Regards, Tone<br>
-- <br>
Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia <br>
(tel: +386-1-477-3523 // fax: +386-1-251-9385)<br>
<br>
<br>
> <br>
> BEGIN<br>
> BEGIN_PATH_INPUT<br>
> &PATH<br>
> restart_mode = 'from_scratch'<br>
> string_method = 'neb'<br>
> nstep_path = 55<br>
> num_of_images = 9<br>
> opt_scheme = 'broyden'<br>
> CI_scheme = 'auto'<br>
> path_thr = 0.05<br>
> k_max = 0.3<br>
> k_min = 0.001<br>
> ds = 0.1<br>
> first_last_opt = .false.<br>
> minimum_image = .true.<br>
> use_freezing = .true.<br>
> use_masses = .true.<br>
> /<br>
> END_PATH_INPUT<br>
> <br>
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