Hi,
I'm trying to simulate an argon drop on a ridged graphene sheet (created in VMD).
Inspite of varying parameters found in the literature, I am unable to produce a stable drop.
The drop spreads out in a continuous film and also evaporates at all sensible parameter values.
The drop is initialized as a cube (produced in PackMOL) situated about 10 Angstrom above the sheet.
The temperatures have been varied from 50K to 85K with to no avail.
My MWE is as follows (from the input file):
dimension 3
units real
boundary p p p
atom_style full
pair_style lj/cut 13.0
# Pair modify also didn't help.
#pair_modify shift yes mix arithmetic
read_data system.data
pair_coeff 1 1 0.2381 3.405
pair_coeff 2 2 0.1680 3.487 # 0.1 more epsilon than the literature
pair_coeff 1 2 0.119 3.44
echo log
thermo 1000
group lj_fluid type 1
group graphite type 2
neighbor 0.3 multi
neigh_modify exclude group graphite graphite check no
fix 1 graphite setforce 0.0 0.0 0.0
fix 2 lj_fluid nvt temp 50 50 10 # 83.005 K
timestep 1
thermo_style custom step temp press pe evdwl etotal
thermo_modify flush yes norm no
restart 500000 x.rest
#dump 1 all custom 10000 z.dump id type x y z
dump 1 all custom 10000 traj_nvt.lammpstrj id mol type x y z ix iy iz
run 2000000
Are such systems unphysical with the force-fields used?
If so, what interactions are suggested for hydrophobicity and hydrophillicity modeling? (basically for contact angle data)