<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>Dear Gromacs Users,</div><div><br></div><div>I am trying to study ligand unbinding adopting Umbrella sampling (using Gmx 4.5.3). during my initial pull to generate configurations for umbrella windows I have pulled in the -Z direction, <br></div><div>@ s0 legend "0 Z"<br>@ s1 legend "1 dZ"<br>0.0000 7.37361 -0.33625<br>0.0200 7.37377 -0.33631<br>0.0400 7.37404 -0.33637<br>0.0600 7.3744 -0.33643<br>0.0800 7.37473 -0.33649</div><div>.</div><div>.</div><div>.</div><div>.</div><div>321.0800 7.37523 -1.29949<br>321.1000 7.37442 -1.29955<br>321.1200
7.37374 -1.29961<br>321.1400 7.37355 -1.29967<br>321.1600 7.37404 -1.29973<br>321.1800 7.37491 -1.29979<br>321.2000 7.3757 -1.29985<br>321.2200 7.37608 -1.29991<br>321.2400 7.37595 -1.29997<br>321.2600 7.37518 -1.30003<br>321.2800 7.37395 -1.30009</div><div>.</div><div>.</div><div>.(so on)<br></div><div><br></div><div>Now when I ran simulations in each umbrella windows, the PMF energies are in negative. My guess is that this is due to my initial setup, or is there something seriously wrong. And if i am right I should get the correct PMF by taking the negative of this PMF (or is it)??<br></div><div>-----</div><div>; Pull code (pulling
simulation)<br>
pull = constraint<br>
pull_geometry = distance <br>
pull_dim = N N Y<br>
pull_start = yes <br>
pull_ngroups = 1<br>
pull_group0 = Protein<br>
pull_group1 = MAL<br>
pull_rate1 = 0.005 ; <br>
pull_k1 = 1000 ; kJ mol^-1 nm^-2<br>
pull_nstxout = 500 ; every 1 ps<br>
pull_nstfout = 500 ; every 1 ps</div>
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<div>-----<br></div><div><br></div><div>; Pull code (Umbrella simulation)<br>pull = umbrella<br>pull_geometry = distance ; <br>pull_dim = Y Y Y<br>pull_start = yes ; <br>pull_ngroups = 1<br>pull_group0 = Protein<br>pull_group1 = MAL<br>pull_rate1 = 0.000 ; <br>pull_k1 = 1000 ; kJ mol^-1 nm^-2<br>pull_nstxout = 500 ; every 1 ps<br>pull_nstfout = 500 ; every 1
ps</div><div><br></div><div><br></div><div>Best,</div><div>nahren<br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div></div></body></html>