[gmx-users] Tau-t should be at least 20 times larger than nsttcouple*dt

[Poncho Arvayo Zatarain]

Hello users: I want to run a simulation with MD run of DPPC+DPPE+Ligand+Water using the command gmx grompp -f md.mdp -c npt.gro -t npt.cpt -p topol.top -n index.ndx -o md_0_1.tpr but when i used it the following warning and error appears:Warning: For proper integration of the Nose-Hoover thermostat, tau-t (0.1) should be at least 20 times larger than nsttcouple*dt (0.01)Fatal error: Too many warnings(1), gmx terminated.Could you help me please?My mdp file is the following:title		= DPPC+DPPE+LIGAND Production MD ; Run parametersintegrator	= md		; leap-frog integratornsteps		= 500000	; 2 * 500000 = 1000 ps (1 ns)dt		    = 0.002		; 2 fs; Output controlnstxout		= 1000		; save coordinates every 2 psnstvout		= 1000		; save velocities every 2 psnstxtcout	= 1000		; xtc compressed trajectory output every 2 psnstenergy	= 1000		; save energies every 2 psnstlog		= 1000		; update log file every 2 ps; Bond parameterscontinuation	= yes		    ; Restarting after NPT constraint_algorithm = lincs	; holonomic constraints constraints	= all-bonds	        ; all bonds (even heavy atom-H bonds) constrainedlincs_iter	= 1		            ; accuracy of LINCSlincs_order	= 4		            ; also related to accuracy; Neighborsearchingns_type		= grid		; search neighboring grid celsnstlist		= 5		    ; 10 fsrlist		= 1.2		; short-range neighborlist cutoff (in nm)rcoulomb	= 1.2		; short-range electrostatic cutoff (in nm)rvdw		= 1.2		; short-range van der Waals cutoff (in nm); Electrostaticscoulombtype	= PME		; Particle Mesh Ewald for long-range electrostaticspme_order	= 4		    ; cubic interpolationfourierspacing	= 0.16		; grid spacing for FFT; Temperature coupling is ontcoupl		= Nose-Hoover		   ; More accurate thermostattc-grps		= DPPC DPPE LIG TIP3	   ; fourth coupling groups - more accuratetau_t		= 0.5	0.5 0.5	 0.1       ; time constant, in psref_t		= 303 	303 303	 303       ; reference temperature, one for each group, in K; Pressure coupling is onpcoupl		= Parrinello-Rahman	    ; Pressure coupling on in NPTpcoupltype	= semiisotropic		    ; uniform scaling of x-y box vectors, independent ztau_p		= 2.0			        ; time constant, in psref_p		= 1.0	1.0		        ; reference pressure, x-y, z (in bar)compressibility = 4.5e-5	4.5e-5	; isothermal compressibility, bar^-1; Periodic boundary conditionspbc		    = xyz		; 3-D PBC; Dispersion correctionDispCorr	= EnerPres	; account for cut-off vdW scheme; Velocity generationgen_vel		= no		; Velocity generation is off; COM motion removal; These options remove motion of the protein/bilayer relative to the solvent/ionsnstcomm         = 1comm-mode       = Linearcomm-grps       = DPPC DPPE LIG TIP3