Dear Gromacs user, I am trying to simulate a protein (nmr structure).I have successfully done energy minimisation step.Also I have equilibrated the system a 298 k (which is achieved from 100 ps run) .Now,I am trying to equilibrate the system at 1 bar pressure.After a run of 100 ps ,I am getting average pressure of the system as 4.9 bar.Then I extended this simulation for 50 ps(total 150 ps from start) ,so the av. pressure dropped to 1.5 bar.Then,I again extended this simulation for further 50 ps(Total 200 ps from start),pressure raised to 2.14 bar.Again ,I extended this simulation for further 50 ps(Total 250 ps),pressure raised to 3.56 bar.Similarly,it av. pressure is 2.98 bar,2.85 bar,2.41 bar for 300ps, 350 ps and 400 ps.I am not able to equilibrate the system at 1 bar pressure.What should be done in these cases?
I am using opls-aa force field,tip-4 water model,for pressure coupling I am using following parameters: ; Pressure coupling is on pcoupl = Parrinello-Rahman ; Pressure coupling on in NPT pcoupltype = isotropic ; uniform scaling of box vectors tau_p = 2.0 ; time constant, in ps ref_p = 1.0 ; reference pressure, in bar compressibility = 4.5e-5 ; isothermal compressibility of water, bar^-1 refcoord_scaling = com note :the initial pressure at the beginning of npt simulation and at the end of nvt simuation is -311.41 bar -- 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
