<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>Dear all, </div><div><br></div><div>When I try to simulation with NVE ensemble, the </div><div>total energy keeps decreasing. Geometry optimization </div><div>and solvent equilibration are done before the NVE simulation. </div><div><br></div><div><div>I follow the requirements provided in </div><div><font class="Apple-style-span" color="#167F7F"><a href="http://www.gromacs.org/Documentation/Terminology/NVE">http://www.gromacs.org/Documentation/Terminology/NVE</a></font></div><div><font class="Apple-style-span" color="#167F7F"><br></font></div></div><div>Would any one help me to figure out what was wrong with</div><div>my settings?</div><div><br></div><div>Millions of thanks and best wishes,</div><div>Yun-an</div><div><br></div><div><font class="Apple-style-span" color="#167F7F"><br></font></div><div>BTW: Please check the following for the .mdp file</div><div><br></div><div><div>;Run control: A leap-frog algorithm for integrating Newton's equations.</div><div>integrator = md</div><div>;time step in femtoseconds</div><div>dt = 0.001</div><div>;number of steps</div><div>nsteps = 10000000</div><div>;No constraints</div><div>constraints = none</div><div>constraint_algorithm = shake</div><div>shake_tol = 1e-08</div><div><br></div><div>; group(s) for center of mass motion removal</div><div>comm-grps = AA CCl4</div><div>; frequency for center of mass motion removal</div><div>nstcomm = 1000</div><div>;frequency to write coordinates to output trajectory file</div><div>nstxout = 1000</div><div>;frequency to write velocities to output trajectory file</div><div>nstvout = 1000</div><div>;frequency to write energies to log file</div><div>nstlog = 1000</div><div>;frequency to write energies to energy file</div><div>nstenergy = 1000</div><div>;group(s) to write to energy file</div><div>energygrps = System</div><div><br></div><div>;Frequency to update the neighbor list (and the long-range forces,</div><div>;when using twin-range cut-off's).</div><div>nstlist = 10</div><div>ns_type = grid</div><div>rlist = 1.5</div><div><br></div><div>; Use periodic boundary conditions in all directions.</div><div>pbc = xyz</div><div><br></div><div>;cut-off distance for the short-range neighbor list</div><div>;treatment of electrostatic interactions</div><div>coulombtype = PME-switch</div><div>fourierspacing = 0.12</div><div>pme_order = 4</div><div>ewald_rtol = 1e-5</div><div>rcoulomb_switch = 1.0</div><div><div>rcoulomb = 1.2</div><div><br></div><div>;treatment of van der waals interactions</div><div>vdwtype = Switch</div><div>rvdw-switch = 1.0</div><div>rvdw = 1.2</div><div>dispcorr = EnerPres</div><div><br></div><div>;Temperature coupling</div><div>tcoupl = no</div><div><br></div><div>;Pressure coupling</div><div>pcoupl = no</div><div><br></div><div>;Velocity generation</div><div>gen_vel = no</div><div><br></div></div><div><br></div></div></body></html>