Hi all, Please suggest me what is the reason for the below situation.
The 1728 TIP4P waters system was simulated in NPT under 1bar maintained with Parrinello-Rahman barostat at 300K. Some results are below: Energy Average RMSD Fluct. Drift Tot-Drift ------------------------------------------------------------------------------- Total Energy -58121.6 344.637 344.476 0.182549 36.5101 Temperature 299.913 4.11684 4.1138 0.00274337 0.548679 Pressure (bar) 1.39811 326.506 317.633 -1.30948 -261.9 Box-X 3.74431 0.00844567 0.00843154 -8.45584e-06 -0.00169118 Density (SI) 984.768 6.66431 6.65307 0.0067005 1.34011 ========================================================== The density is stable and the system looks like equilibrated one. The output GRO was then renamed to conf.gro and the average Box-X from the previous run was set as the cubic box side length. The barostat was switched off with no other changes in MDP. The same properties for NVT are below: Energy Average RMSD Fluct. Drift Tot-Drift ------------------------------------------------------------------------------- Total Energy -58075.8 309.575 308.343 -0.477939 -95.5887 Temperature 299.916 4.08901 4.08678 -0.00233712 -0.467428 Pressure (bar) -18.5469 286.376 285.574 0.37081 74.1628 So the pressure in NPT is ~1.4 and in NVT is ~(-19). How to explain so big difference in average values? Is it possible to get a value of around 1 in the NVT? Thank you. Vitaly -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
