I have a drude system that I have minimized, and equilibrated through nvt and npt ensembles using position restraints (all with scf). As I perform the production runs i’m facing random crashes that seem to be related to EM did not converge messages. This has happened anywhere from tens of thousands of steps in, to millions of steps in. Below is an example and the mdp options for the run.
My Best, Guy Dayhoff -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= step 393698: EM did not converge in 20 iterations, RMS force 15.668 step 393699: EM did not converge in 20 iterations, RMS force 88.569 step 393700: EM did not converge in 20 iterations, RMS force 341.002 step 393701: EM did not converge in 20 iterations, RMS force 680.888 step 393702: EM did not converge in 20 iterations, RMS force 1147.229 step 393703: EM did not converge in 20 iterations, RMS force 1077.486 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= MDP options: ; RUN CONTROL integrator = md nsteps = 50000000 ;50ns dt = 0.001 ; OUTPUT CONTROL nstxout = 0 nstvout = 10000 ;every 10ps for now nstfout = 10000 nstlog = 10000 nstenergy = 10000 nstcalcenergy = 1 nstxout-compressed = 10000 compressed-x-grps = System ; NEIGHBOR SEARCHING cutoff-scheme = verlet nstlist = 10 ns-type = Grid pbc = xyz rlist = 1.2 ; BONDS constraints = h-bonds continuation = yes ; ELECTROSTATICS AND VdW coulombtype = PME rcoulomb = 1.2 vdwtype = cutoff vdw-modifier = potential-switch rvdw-switch = 1.0 rvdw = 1.2 DispCorr = EnerPres ; EWALD pme_order = 4 fourierspacing = 0.16 ; TEMPERATURE COUPLING Tcoupl = Nose-Hoover tc-grps = Water non-Water tau_t = 10.0 10.0 ref_t = 300 300 nh-chain-length = 1 ; VELOCITY GENERATION gen-vel = no ; PRESSURE COUPLING Pcoupl = Parrinello-Rahman Pcoupltype = semiisotropic tau_p = 50.0 compressibility = 4.5e-5 4.5e-5 ref_p = 0.0 3.0 ; DRUDE POLARIZATION drude = yes drude-mode = SCF drude-hyper = yes drude-khyp = 16736000.0 drude-r = 0.02 drude-pow = 4 -- 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.