bad result when simulate evaporation of waters

Dear lammps experts,

I used spc water in lammps-11Aug17 to simulate evaporation of droplet into Nitrogen, but the droplet could not diffuse at 423K and 0.1MPa, which made me confused. Could you tell me why I met the wrong result? The configuration of water was constructed by moltemplate. Here is my input script. Input data can be enclosed if you want.

------------------------------- Initialization Section --------------------

units real
atom_style full
bond_style hybrid harmonic
angle_style hybrid harmonic
pair_style lj/cut/coul/long 10 10
pair_modify mix geometric
special_bonds lj/coul 0.0 0.0 0.5
kspace_style pppm/cg 0.0001
boundary p p p
read_data waters.data

------------------------------- Settings Section --------------------------

pair_coeff 1 1 0.1554 3.16557
pair_coeff 2 2 0.0 0.0
pair_coeff 3 3 0.167 3.50123
bond_coeff 1 harmonic 600.0 1.0
bond_coeff 2 harmonic 1632.5100 1.0976
angle_coeff 1 harmonic 75.0 109.47
set type 1 charge -0.82
set type 2 charge 0.41
set type 3 charge 0

------------------------------- Run Section -------------------------------

thermo 100
thermo_style custom step temp etotal press ke pe
neighbor 2 bin
neigh_modify delay 0 every 1 check yes
region heat sphere 0 0 0 80 side out
dump dumpeq3 all custom 2000 423nvt.lammpstrj id mol type x y z ix iy iz

------------------------------- eqnph -------------------------------

timestep 2
fix fxlan all langevin 300.0 300.0 120 123456
fix fxnph all nph iso 1.0 1.0 2000.0
run 4000
unfix fxlan
unfix fxnph

------------------------------- eqlangevin -------------------------------

fix fxlan all langevin 423.0 423.0 120 48279
fix fxnve all nve
run 4000
unfix fxlan
unfix fxnve

------------------------------- eqnvt -------------------------------

fix fxnvt all nvt temp 423.0 423.0 500.0 tchain 1
fix 9 all evaporate 1000 100 heat 199417 molecule yes
fix 14 all momentum 1 linear 1 1 1 rescale
fix 15 all recenter INIT INIT INIT
run 50000

Yours Sincrely,

Shuwen Yang

I used spc water in lammps-11Aug17 to simulate evaporation of droplet into Nitrogen, but the droplet could not diffuse at 423K and 0.1MPa, which made me confused. Could you tell me why I met the wrong result?

It's not clear to me what you mean by "the wrong result". Can you
clarify what happened, and what you expected to happen? It's okay if
you want to attach a picture (if the problem can be demonstrated with
a picture).

Also, in the final step ("eqnvt"), why do you use "fix momentum" and
"fix recenter". (Don't these two fixes oppose each other?) What
happens if you omit them both?

Andrew