I want a constant energy simulation at 0.01 K . Is it possible. I
cannot keep increasing my cut off because for that i have to increase
my box size. <br>
I have tried so many times but the temperature increases and neither is the energy constant. :(<br>
-<br>
karamyog. :(<br><br><div><span class="gmail_quote">On 5/19/06, <b class="gmail_sendername">karamyog singh</b> <<a href="mailto:karamyog.singh@gmail.com">karamyog.singh@gmail.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>I guess since after the first run, the forces between atoms is not
zero(only negligible), when i do the 2nd run, the atoms start moving
under the action of these forces and since there is no temperature
scaling or pressure scaling, we can or might see an increase in KE as
in my case. So an increase might be correct.<br>
Am I right? Please answer this because I am an undergraduate student and this will clear my misconception, if any. :)<br>
Thanks in advance.<br>
-<br></div><div><span class="sg">
Karamyog.<br><br></span></div><div><div></div><div><span class="q"><span class="gmail_quote">On 5/18/06, <b class="gmail_sendername">Mark Abraham</b> <<a href="mailto:Mark.Abraham@anu.edu.au" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
Mark.Abraham@anu.edu.au</a>> wrote:</span></span></div><div><span class="e" id="q_10b4ba4d80cdae7d_4"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
karamyog singh wrote:<br>> Well, I am back. Remember my first and second mdruns. In my second,<br>> after stablizing my initial configuration in the 1st md run, I used cut<br>> off upto 6.3 whereas the potential minima is at
0.309. 6.3 is quite<br>> large a distance compared to 0.309. In the second run, the kinetic<br>> energy increases which is correct but the total energy doesnt seem to<br>> remain constant even when there are 3 million steps involved.
<br><br>Why is increasing KE correct?<br><br>> How is this constant energy mode? KE increases(accepted) but the total<br>> never seems to be constant. I cant keep increasing my no. of steps.<br>> moreover how can so many vibrations be introduced at a temp. of
0.001 K.<br><br>It's well known (as I said a few emails ago) that cut-offs in NVE will<br>cause system heating - that's why people tend to use NVT if they are<br>using cut-offs. Expected NVE behaviour for this sort of system as a
<br>function of cut-off is outside my experience, but you can use g_energy<br>to judge how fast KE and thus total energy is increasing as a function<br>of simulation time. If that rate varies with the cutoff, then I'd say
<br>there's the problem.<br><br>Mark<br>_______________________________________________<br>gmx-users mailing list <a href="mailto:gmx-users@gromacs.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
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