LAMMPS中wall的应用

Posted by XiLock on September 24, 2020

周期性

boundary

boundary     p p f


boundary     p p s

kspace

boundary        p p f
pair_style      lj/charmmfsw/coul/long 11 12
kspace_style    pppm 0.001
kspace_modify   slab 3.0


fix wall/reflect

Bound the simulation with one or more walls which reflect particles in the specified group when they attempt to move through them.
Reflection means that if an atom moves outside the wall on a timestep by a distance delta (e.g. due to fix nve), then it is put back inside the face by the same delta, and the sign of the corresponding component of its velocity is flipped.

fix wall/lj126

Bound the simulation domain on one or more of its faces with a flat wall that interacts with the atoms in the group by generating a force on the atom in a direction perpendicular to the wall. The energy of wall-particle interactions depends on the style.

# parameter value is epsilon, sigma, and cutoff respectively.
fix wall1 all wall/lj126 zlo EDGE 0.1 1.0 2.5
fix wall2 all wall/lj126 zhi EDGE 0.1 1.0 2.5


通过压缩壁面控制体系密度

soft势

pair_style     soft 2.0
pair_coeff     * * 50.0

壁面压缩

variable    z equal 311-0.001*elapsed
fix         1 all nvt temp 300.0 300.0 100.0
#fix         2 all langevin 300.0 300.0 80.0 699483
fix         3 all wall/reflect zlo EDGE zhi v_z
timestep    1.0
run         267400


lj势

pair_style     lj/cut 10.0
pair_coeff     * * 0.112 4.01