Hello,<br><br>I have run 2 ns simulations on a hydrocarbon system (initial density of ~ 2 SI and box size is 15 nm), one with version 4.0.7 and the other trial using 4.5.3. Both runs are almost equilibrated to 70 bar pressure but one is giving density of above 600SI (4.0.7) and the other density of around 15 SI (4.5.3). With 4.5.3 applying 100 bar pressure does not comrades the system either to the desired density. I need to study the system at different pressures from 1 to 70 bar, and I am wondering if the system can not be compressed with these ref_p values how can I keep the pressure fixed at P < 70 bar!? <br>
<br>Please help if you have any idea on why these two versions are giving inconsistent results and which one is reliable. <br><br>Thanks so much,<br><br><br>4.0.7 <br><br>Statistics over 250001 steps [<b> 1500.0001 thru 2000.0001 ps ],</b> 14 data sets<br>
The term 'Cons. rmsd ()' is averaged over 2501 frames<br>All other averages are exact over 250001 steps<br><br>Energy Average RMSD Fluct. Drift Tot-Drift<br>-------------------------------------------------------------------------------<br>
Angle 36.9945 0.806738 0.804483 0.0521993 0.208798<br>Ryckaert-Bell. 9.04227 0.376253 0.371412 0.0521057 0.208424<br>LJ-14 5.23048 0.119612 0.119611 0.00033983 0.00135933<br>
Coulomb-14 -1.66329 0.104171 0.102175 0.0175753 0.0703015<br>LJ (SR) -27.3967 0 0 0.0421934 0.168774<br>Coulomb (SR) 8.98711 0.163579 0.16062 -0.0268199 -0.10728<br>
Potential 31.1944 0 0 0.137594 0.550377<br>Kinetic En. 51.1009 0.987759 0.987724 0.00725949 0.0290381<br>Total Energy 82.2953 0 0 0.144851 0.579408<br>
Temperature 299.98 5.79849 5.79828 0.000340897 0.170449<br><b>Pressure (bar) 69.3587 414.279 414.256 0.0298385 14.9193</b><br>Cons. rmsd () 4.01744e-06 1.41883e-07 1.41883e-07 0 0<br>
<b>Box-X 3.04882 0 0 3.57512e-06 0.00178757<br>Box-Y 3.04882 0 0 3.57512e-</b><br><br><br>-----------------------------<br>4.5.3. <br><br>[<b> 1500.0001 thru 2000.0001 ps ],</b><br>
<br>Energy Average Err.Est. RMSD Tot-Drift<br>-------------------------------------------------------------------------------<br>Angle 37.1357 0.071 0.812307 -0.099711 (kJ/mol)<br>
Ryckaert-Bell. 9.17677 0.14 0.445934 -0.529281 (kJ/mol)<br>LJ-14 5.18878 0.0087 0.137673 -0.03119 (kJ/mol)<br>Coulomb-14 -1.60372 0.051 0.126405 -0.144403 (kJ/mol)<br>
LJ (SR) -4.24478 0.29 0.742141 0.697187 (kJ/mol)<br>Coulomb (SR) 8.97451 0.082 0.198278 0.232025 (kJ/mol)<br>Potential 54.6272 0.31 1.20733 0.124627 (kJ/mol)<br>
Kinetic En. 51.1047 0.021 0.9945 -0.066306 (kJ/mol)<br>Total Energy 105.732 0.31 1.58869 0.058321 (kJ/mol)<br>Temperature 300.002 0.12 5.83806 -0.389239 (K)<br>
<b>Pressure 66.734 5.3 91.83 11.5294 (bar)</b><br>Constr. rmsd 2.2661e-10 2.3e-10 3.58302e-08 -1.3595e-09 ()<br><b>Box-X 11.0055 0.082 0.175309 -0.496198 (nm)<br>
Box-Y 11.0055 0.082 0.175309 -0.496198 (nm)</b><br><br><br><br><br> <br><br>pbc = xyz<br> <br>integrator = md <br>
dt = 0.002 <br>nsteps = 1000000 <br>nstcomm = 100 <br>nstenergy = 100 <br>nstxout = 100 <br>
<br>nstlist = 10 <br>ns_type = grid <br><br>coulombtype = Shift<br>vdw-type = Shift <br>rcoulomb-switch = 0 <br>
rvdw-switch = 0.9 <br>rlist = 1.2 <br>rcoulomb = 1.2 <br>rvdw = 1.0 <br><br>Tcoupl = v-rescale <br>
tc-grps = System <br>tau_t = 0.1 <br>ref_t = 300 <br> <br><br>Pcoupl = berendsen<br>Pcoupltype = isotropic <br>
tau_p = 1 <br>compressibility = 4.5e-5 4.5e-5 <br>ref_p = 70 <br><br><br>gen_vel = yes <br>gen_temp = 300.0 <br>
gen_seed = 173529 <br><br><br>
constraints = all-bonds <br>
constraint-algorithm = lincs <br><br>