<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div>you could use position restrains on the other atoms (non hydrogens) or use freezing groups.<div><br></div><div>it seems that your system has a major problem: bad contacts ... check it prior to EM.</div><div><br><div><div>On Jul 6, 2009, at 8:30 AM, nitu sharma wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Dear all <br><br><br> I have to apply only Hydrogen molecule will be relax during energy minimization of protein molecule.<br><br>can anyone have idea about what short of changes I have to make in em.mdp file to allow only hydrogen molecule is relaxable during energy minimisation?<br> my em.mdp file like this-<br><br>cpp = /usr/bin/cpp<br>define = -DFLEX_SPC<br>constraints = none<br>integrator = steep<br>dt = 0.001<br>nsteps = 100<br> <br>;<br>; Energy minimizing stuff<br>;<br>emtol = 10<br>emstep = 0.01<br>nstcgsteep = 1000<br>nstcomm = 1<br>nstlist = 10<br>ns_type = grid<br> rlist = 1.0<br>rcoulomb = 1.0<br>vdw-type = cut-off<br>rvdw = 1.0<br>coulombtype = PME<br>Tcoupl = no<br>Pcoupl = no<br>gen_vel = no<br> comm-mode = Linear<br>pbc = XYZ<br>Thanks a lot in advance.<br><font color="#888888"><br>Nitu sharma.<br> </font> _______________________________________________<br>gmx-users mailing list <a href="mailto:gmx-users@gromacs.org">gmx-users@gromacs.org</a><br><a href="http://lists.gromacs.org/mailman/listinfo/gmx-users">http://lists.gromacs.org/mailman/listinfo/gmx-users</a><br>Please search the archive at http://www.gromacs.org/search before posting!<br>Please don't post (un)subscribe requests to the list. Use the <br>www interface or send it to gmx-users-request@gromacs.org.<br>Can't post? Read http://www.gromacs.org/mailing_lists/users.php</blockquote></div><br></div></body></html>