Hi dear lammps users
I use read data to generate initial coordinates of an aqueous solvent (H2O + Na+ + Cl- ) between two parallel crystalline walls, But my thermo output shows very high pressure. I use real units and my initial pressure becomes about 5000000 wich decreases to 450000 after the Energy minimization. So what is your idea about this problem?
The minimum distance between my atoms is 2.3 A0 and this amount increases to 7.7 A0 for distance between my ions. Also the lattice of wall is diamond and it’s constant is 5.43095 A0 .
there is 2 A0 distance between periodic boundaries or walls and solvent initial coordinates borders. So I think there is not overlap in me system. In addition I use energy minimization and then I permit my system to relax.
Another problem is that when I remove walls, the pressure increases abnormally!
Data file:
LAMMPS Description
7426 atoms
4288 bonds
2144 angles
0 dihedrals
0 impropers
6 atom types
1 bond types
1 angle types
-2 48.6 xlo xhi
-2 44.2 ylo yhi
-6 41 zlo zhi
Masses
1 1.00794
2 15.99943
3 35.453
4 22.98976928
5 28.09
6 28.09
.
.
.
.
Input file:
units real
neighbor 0.3 bin
neigh_modify delay 0 every 1 check yes
boundary p p f
processors 1 1 1
atom_style full
bond_style harmonic
angle_style harmonic
pair_style lj/cut/coul/long 11
kspace_style pppm 1e-4
kspace_modify slab 3.0
.
.
.
Thanks a lot for your advice
Best regard
Majid Rezaei
Hi dear lammps users
I use read data to generate initial coordinates of an aqueous solvent (H2O +
Na+ + Cl- ) between two parallel crystalline walls, But my thermo output
shows very high pressure. I use real units and my initial pressure becomes
about 5000000 wich decreases to 450000 after the Energy minimization. So
what is your idea about this problem?
either your potential parameters are wrong or your density is wrong.
The minimum distance between my atoms is 2.3 A0 and this amount increases to
7.7 A0 for distance between my ions. Also the lattice of wall is diamond and
it's constant is 5.43095 A0 .
so?
there is 2 A0 distance between periodic boundaries or walls and solvent
initial coordinates borders. So I think there is not overlap in me
system. In addition I use energy minimization and then I permit my system to
relax.
the system can only relax, if there is space to relax into,
Another problem is that when I remove walls, the pressure increases
abnormally!
???
well, what about kinetic energy.
Data file:
this is useless, since it is incomplete
and has no useful information.
LAMMPS
Description
7426
atoms
4288
bonds
2144
angles
0
dihedrals
0
impropers
6 atom
types
1 bond types
1 angle
types
-2 48.6 xlo xhi
-2 44.2 ylo yhi
-6 41 zlo zhi
Masses
1
1.00794
2
15.99943
3
35.453
4
22.98976928
5
28.09
6 28.09
.
.
.
.
Input file:
units real
neighbor 0.3 bin
neigh_modify delay 0 every 1 check yes
boundary p p f
processors 1 1 1
atom_style full
bond_style harmonic
angle_style harmonic
pair_style lj/cut/coul/long 11
kspace_style pppm 1e-4
kspace_modify slab 3.0
also incomplete and thus useless.
Thanks a lot for your advice
please provide a better description
of your problem. nobody can give
good advice with too little tangible
information.
axel.