Yes, the water droplet should remain a droplet on graphene. Since you have a droplet, I assume you have much vacuum in the system. I would not use PME for such system, but would rather "compensate" it by using larger cutoffs.
If you need a simple advice, it is -- enlarge the box to avoid any interactions, which you would not have had in real experiment. I also expect a specific behavior, if your droplet is very small. Maybe, I would simulate this system without PBC at all. Dr. Vitaly Chaban > I have a graphene like surface (carbons on a hexagonal lattice with zero > partial charges and some LJ parameters) with a drop of water placed on it. > In principle, this is a hydrophobic surface and the drop should remain a > droplet on it. However, surprisingly I am seeing that the drop is spreading > within a 1 ns of the simulation. In the past I have done some similar > simulations (with a different structure but basically zero partial charge > surface and LJ) on which the drop remains a drop. > > Does any body have any ideas of what I may be doing wrong? Pasted below is > my mdp and top file. Briefly, I am doing NVT simulation, PME for > electrostatics, TIP3P water model, the surface is frozen and intra-surface > interactions are excluded, the cut-off distances are 1 nm, velocity rescale > thermostat (I tried both with the entire system coupled to the same > thermostat and with sheet and water being coupled to different > thermostats). > Any suggestions are welcome. > > My analysis suggests this comes from the long range electrostatics because > we have tested the same thing in LAMMPS. When we turn off PPPM and use > cut-off based Coulomb (~5 nm) in LAMMPS (yes now we have changed the > software) we don't see the drop spreading. > > I have done so many simulations and to have this problem stumps me!! Thanks > for being helpful always. > -- 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
