Hello!
I’m trying to calculate a liquid-solid interface with any potentials. The system is composed of a ionic liquid(IL), which is sandwiched by two graphene(GR) sheets, such as GR|IL|GR. The potential is applied by charging graphene.
My problem is that no yeh-berkovitz correction is applied to the system. Without correction, the potential profile vs depth is not parallel in the range of bulk. In the mdp file, the correction is “ewald-geometry=3dc”.
The details of the system are following;
・gromacs2021.2
・system：
EAN(ethylammonium nitrate)：1500 ion pairs
graphene：836 atoms / one sheet, about 4.6 nm*4.6 nm
・box：
x, y length are same to a graphene sheet
z length is 80 nm(>liquid depth is about 11 nm)
・force field is oplsaa
・mdp file is
;1.Run control
integrator = md
dt = 0.002
nsteps = 15000000
comm-mode = Linear
;3.Output control
nstxout = 5000
nstvout = 5000
nstfout = 5000
nstlog = 5000
nstcalcenergy = 5000
nstenergy = 5000
nstxout-compressed = 5000
;4.Neighbor searching
cutoff-scheme = verlet
nstlist = 10
ns_type = grid
rlist = 1.2;nm
;5.Electrostatics
coulombtype = PME
rcoulomb = 1.2
;6.Van der Waals
vdwtype = Cut-off
rvdw = 1.2
DispCorr = EnerPres
fourierspacing = 0.12 ; [nm] grid spacing for FFT grid when using PME
pme_order = 4 ; interpolation order for PME, 4 = cubic
ewald_rtol = 1e-05 ; relative strength of Ewald-shifted potential at rcoulomb
;6.Temperature coupling
tcoupl = v-rescale
tc-grps = system
tau-t = 2.0;ps
ref-t = 400;K
;7.Pressure coupling
pcoupl = no
pcoupltype = isotropic
tau-p = 4.0;ps
ref-p = 1.0;bar
compressibility = 4.5e-5;/bar
;7.Velocity generation
gen-vel =no
gen-temp = 400
;8.Bonds
constraints = h-bonds
constraint-algorithm = LINCS
continuation = yes
lincs-order = 4
lincs-iter = 1
pbc = xy ; Periodic Boundary Conditions (yes/no)
ewald-geometry = 3dc
nwall = 2
wall-type = 10-4
wall-atomtype = C_w C_w
wall-density = 120 120
freezegrps = GP GN
freezedim = Y Y Y Y Y Y
periodic-molecules = yes
Please give me any advice.
