GROMACS version:2021.7 and 2023.4
GROMACS modification: No
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Dear all，
When I simulated a large water system (100000 water molecules) using the TIP5P water model, it was vaporized at 273K and 1bar. The initial structure was built using ‘gmx solvate’, followed by an energy minimization. Using the same procedure for smaller systems (10000 water molecules), I can get equilibrated liquid water. I also tested the simulation with the TIP4P model for larger systems, it also works well. The mdp and top files used for the simulation are provided below:
#-----top----------
Include forcefield parameters
#include “amber99sb.ff/forcefield.itp”
#include “amber99sb.ff/tip5p.itp”
[ system ]
; Name
ICE in water
[ molecules ]
; Compound #mols
SOL 110310
#--------------------
#----mdp--------
constraints = hbonds
constraint_algorithm = LINCS
integrator = md
dt = 0.002 ; ps !
nsteps = 5000000 ;
nstxout = 0
nstvout = 0
nstfout = 0
nstlog = 5000
nstenergy = 500
nstxtcout = 500
nstlist = 10
cutoff-scheme = verlet
ns_type = grid
coulombtype = PME
rlist = 0.9
rcoulomb = 0.9
rvdw = 0.9
pbc = xyz
optimize_fft = yes
nstcomm = 100
comm-grps = System
tcoupl = V-rescale
tc-grps = system
tau_t = 2
ref_t=273
energygrps = system
Pcoupl = C-rescale
Pcoupltype = isotropic
tau_p = 5
compressibility = 4.5e-5
ref_p=1
gen_vel = yes
gen_temp=273
gen_seed = -1
dispcorr =Enerpres
#------------------------------------
Here are some of the physical quantities (E,T,P,rho) in the simulation
tip5p.xvg (28.2 KB)
Thanks,
Xuan