[gmx-users] No Checkpoint File generated

[Chunlei ZHANG]

Dear All,

I am doing a md simulation for a system consisting of protein with 1.5ns
thick water shell.
The whole system is simulated in vacuum.
I turn of PBC and cutoffs for nonbond interactions.

Now, the simulation runs well, but no checkpoint file is output.
Does anyone know the issue?
The parameters in .mdp file is appended.

Thanks in advance.

Chunlei

*********************************************************************************************

define = -DPOSRES -DFPOSRES ; position restrain the protein
; Run parameters
integrator = md ; leap-frog integrator
nsteps = 250000 ; 2 *  25 000 = 50 ps
dt = 0.002 ; 2 fs

; Output control
nstxout = 0 ; save coordinates every 1 ps
nstvout = 0 ; save velocities every 1 ps
nstxtcout = 500 ; save compressed coordinates very 1 ps
nstenergy = 500 ; save energies every 1 ps
nstlog = 500 ; update log file every 1 ps
; Bond parameters
continuation = no ; continue from nvt run
constraint_algorithm = lincs ; holonomic constraints
constraints = all-bonds ; all bonds (even heavy atom-H bonds) constrained
lincs_iter = 1 ; accuracy of LINCS
lincs_order = 4 ; also related to accuracy
; Neighborsearching
ns_type = simple ; search neighboring grid cels
nstlist = 0 ; 10 fs
rlist = 0 ; short-range neighborlist cutoff (in nm)
rcoulomb = 0 ; short-range electrostatic cutoff (in nm)
rvdw = 0 ; short-range van der Waals cutoff (in nm)
vdwtype = cut-off ; twin-range cut-off for vdw interation
coulombtype = cut-off ; Particle Mesh Ewald for long-range electrostatics
; Temperature coupling is on
tcoupl = V-rescale ; modified Berendsen thermostat
tc-grps = Protein SOL RWW ; two coupling groups - more accurate
tau_t = 0.1 0.1 0.1 ; time constant, in ps
ref_t = 300 300 300 ; reference temperature, one for each group, in K
; Pressure coupling is off
pcoupl = no ; no pressure coupling in NVT
; Periodic boundary conditions
pbc = no ; 3-D PBC
comm_mode       = ANGULAR
nstcomm         = 1