Here is my script. Thank you all
# Argon Surface tension
units real
atom_style atomic
lattice fcc 5.26
boundary p p p
region box1 block -3.0 3.0 -3.5 3.0 -10 10
region box2 block -2.5 2.5 -2.5 2.5 -2.5 2.5
create_box 1 box1
create_atoms 1 region box2
# forcefield
mass 1 39.948 # Ar
pair_style lj/cut 8.7675
pair_coeff 1 1 0.233 3.507 8.7675
variable Nrun equal 500000
variable A_in_m equal 1e-10 # Angstrom in meter
variable atm_in_Pa equal 101325 # note: 1 Pa = 1 N/m^2
variable N_in_mN equal 1e3 # Newton in milliNewton
variable convFac equal ${A_in_m}*${atm_in_Pa}*${N_in_mN}
variable Text equal 100
group Argon type 1
velocity all create ${Text} 1234
neighbor 2.0 bin
neigh_modify delay 10 check no
fix 1 all nve
fix thermostat all langevin ${Text} ${Text} 100 1234 zero yes
fix 2 all temp/berendsen 100.0 100.0 100.0
compute T all temp
fix TAve all ave/time 10 100 1000 c_T
variable P equal press
fix PAve all ave/time 10 100 1000 v_P
variable xPress equal c_thermo_press[1]
variable yPress equal c_thermo_press[2]
variable zPress equal c_thermo_press[3]
# Evaluate and average surface tension in mN/m:
variable st equal 0.5*lz*(v_zPress-0.5*(v_xPress+v_yPress))*${convFac}
fix st all ave/time 10 100 1000 v_st
variable xyArea equal lx*ly
thermo_style custom step temp f_TAve press f_PAve v_zPress etotal v_xyArea lz f_st
thermo 1000
dump trj all custom 1000 Argon.trj id type x y z
timestep 1
run_style verlet
run ${Nrun}
Hi Nezar Snobar,
You can check your stress component. I recommend that you should check kinetic and virial stress separately for your system and find out which part is the reason for this fluctuation. Also, you should be careful bin size selection and use the longer run time to reduce fluctuation. The following paper would help you to calculate surface tension according to stress value.
https://link.springer.com/article/10.1007/s10404-021-02455-6
- Badges
- Science topic
- Similar topics
- Engineering
- Computer Engineering
- Computer