Dear all,
I want to produce strongly coupled electron-ion plasma. I am using pair_style Coulomb/long, at low temperature or high coupling (e^2/(4piepsilon_0Kba*T)) because of attractive electron-ion Coulombic potential particle collapses. For removing collapse i want to introduce a interaction potential of type given as
(e^2/(4piepsilon_0r))(1- exp(- r/lemda))
where lemda is de Broglie wave length. It is combination of Coulomb and Yukawa. How i produce such type of pair_style in LAMMPS.
Plese help regarding production of this pair_style. My script is given below-
#3D box simulation
Parameters and constants
variable lu equal 1e-7
variable Q1 equal 1.6e-19
variable Q2 equal -1.6e-19
variable ctf equal 5*{lu}
variable inner equal 0.01*{lu}
variable outer equal {ctf}
variable dtsp equal 1e-15
variable V equal vol
variable T equal 140
variable b equal 3*{lu}
#Initialization
units si
atom_style charge
newton on
dimension 3
boundary p p p
#Atom definition
lattice bcc ${lu}
region simbox block 0 10 0 10 0 10 units lattice
create_box 2 simbox
create_atoms 2 region simbox basis 1 1 basis 2 2
assume type 1 is positive
group cp type 1
group cn type 2
set group cp charge {Q1}
set group cn charge {Q2}
Force field
pair_style coul/long ${ctf}
pair_coeff * *
kspace_style ewald 1.0e-10
pair_modify table 0
dielectric 1.0
#Settings
neighbor ${b} bin
neigh_modify every 1 delay 0 check yes one 10000 page 100000
mass 1 1.6708e-27
mass 2 9.1e-31
temperature controller
compute new3d all temp
equilibrate
At 140 K
velocity all create {T} 5812775 temp new3d units box
fix eq1 all nvt temp {T} ${T} 1e-13
thermo_style custom step temp ecoul ke etotal
thermo 200
dump 1 all atom 200 yes.dump
pair_write 1 2 20000 rsq {inner} {outer} table.txt coul_long_Q1_Q2 {Q1} {Q2}
timestep ${dtsp}
run 20000
Thanks & Regards
SANDEEP KUMAR
INSTITUTE FOR PLASMA RESEARCH
GANDHINAGAR, GUJARAT (INDIA), 382428