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On 10/07/2011 9:01 PM, chicago.ecnu wrote:
<blockquote cite="mid:201107101901261714171@gmail.com" type="cite">
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<div>Dear Gromacs Users,</div>
<div> </div>
<div> Harmonic potentials are used in Gromacs for imposing
restraints on the motion of the system.</div>
<div> </div>
<div> V = 1/2 * k * (x-x0)^2</div>
<div> </div>
<div> And the forces are : F = -k * (x-x0) . ...</div>
<div> </div>
<div> I want to use constant force for the restraint. </div>
<div> </div>
<div> Just scale the force : F = -k * (x-x0) / sqrt (
(x-x0)**2+(y-y0)**2 + (z-z0)**2 ) ...</div>
</blockquote>
<br>
Why? That will not be very stable.<br>
<br>
<blockquote cite="mid:201107101901261714171@gmail.com" type="cite">
<div> </div>
<div> This was very simple.</div>
<div> </div>
<div> But I don't know where the position restraint code is . </div>
<div> </div>
<div> Could you please tell me where I can start with ? </div>
</blockquote>
<br>
Check out this thread for clues on how to search the code : <a
href="http://lists.gromacs.org/pipermail/gmx-developers/2008-October/002856.html">http://lists.gromacs.org/pipermail/gmx-developers/2008-October/002856.html</a><br>
<br>
Mark<br>
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