Dear all,
I try to perform CO2 density by EPM2 model at temperature 318K pressure 20MPa. The density of experimental data was 0.84. Unfortunately, the result of simulation was 0.27 wihch I did. But most of the literature simulated the correct density with EPM2 model.
Parameters and input file see below. Can you give me some advice or tell me where I can get help? Thankyou very much.
Sincerely，
Muhan
----------------- Settings Section -----------------
bond_coeff 1 450.0 1.149
angle_coeff 1 295.411 180.0
pair_coeff 2 2 0.1560 3.003
pair_coeff 1 1 0.0559 2.757
pair_coeff 1 2 0.0945 2.892
----------------- Run Section -----------------
include “system.in.init”
read_data “system.data”
include “system.in.settings”
minimize 1.0e-8 1.0e-8 5000 50000
reset_timestep 0
timestep 1.0
thermo 100
thermo_style custom step cpu temp press etotal
dump 1 all custom 1000 co2con.lammpstrj id mol type x y z ix iy iz
fix fxnve all nve
run 10000
unfix fxnve
fix fxnvt all nvt temp 318.0 318.0 10000.0
run 100000
unfix fxnvt
fix fxnpt all npt temp 318.0 318.0 100.0 iso 200.0 200.0 1000.0
run 1000000