[gmx-users] water dynamics

[Eduardo Oliveira]

Hi all,

I was preparing my system for a simulation and after using grompp i got the following message:

Fatal error:
Invalid T coupling input: 2 groups, 1 ref_t values and 1 tau_t values
For more information and tips for troubleshooting, please check the GROMACS

for more information here goes the mdp file:


title                    = 500ps_pr_fixo
cpp                      = /lib/cpp
define                   = -DPOSRES
integrator               = md
tinit                    = 0
dt                       = 0.002
nsteps                   = 250000 ; total 500 ps
comm-mode                = Linear
nstcomm                  = 1
nstxout                  = 500
nstvout                  = 20000
nstfout                  = 20000
nstlog                   = 1000
nstenergy                = 100
nstxtcout                = 500
xtc-precision            = 1000
energygrps               = Protein SOL CL- 3
nstlist                  = 5
ns_type                  = grid
pbc                      = xyz
rlist                    = 1.0
domain-decomposition     = no
coulombtype              = PME
rcoulomb                 = 1.0
epsilon-r                = 1
vdw-type                 = Cut-off
rvdw                     = 1.0
DispCorr                 = EnerPres
optimize_fft             = yes
Tcoupl                   = V-rescale ;berendsen
tc-grps                  = Protein Non-Protein  
tau-t                    = .1     
ref-t                    = 310     
gen_vel                  = yes
gen_temp                 = 310
gen_seed                 = 173529
Pcoupl                   = berendsen
Pcoupltype               = Isotropic
tau-p                    = 1
compressibility          = 4.5e-5
ref-p                    = 1
constraints              = all-bonds
constraint-algorithm     = Lincs
unconstrained-start      = no
Shake-SOR                = no
shake-tol                = 1e-04
lincs-order              = 4
lincs-warnangle          = 30
morse                    = no