Hello, Thank you both for the comments. I am using gromos96 forcefield . I read a little bit and as you said the nonbonded cutoff has to be higher. The tau_p=5ps was chosen , since the manual mentions that the value has to be raised by 4-5 times on going from berendsen to parrinello-rahman barostat, though I did not completely follow the reasons behind it. I will try with lower values.
I had run an earlier simulation with the same parameters for a pure water system for 5ns and reference pressure 5bar, and things worked fine there with the average pressure at 5.15bar. I guess the sigma for the case of water was low and therefore the small cut-off of 0.8nm did not matter. However the case of cyclohexane alone remains to be tried. I guess Dr Vitaly was saying about using a switch/shift function. I will try the simulation with the new settings and see. Regards, Sujith. -- View this message in context: http://gromacs.5086.x6.nabble.com/Dubious-results-with-NPT-tp5014731p5014759.html Sent from the GROMACS Users Forum mailing list archive at Nabble.com. -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.