Dear friends, i have questions.
2D calculation with periodic z,y boundary conditions: charged atomic monolayer till the boundaries on y and z and 1 electron. As i expect, periodic boundaries should make the film effectively infinite, and force acting on electron should be (at least approximately) constant. I did the calculation (see script below). I see the x-force changes several times:
x-force x-coordinate
-0.08036434583 39.99989954
-0.09134284659 30.14369274
-0.1058546564 20.44464086
-0.1421158834 10.28546875
-0.2095791418 6.022522952
change and value of y-force (which shows the nonhomogeniosity in charge distribution) is less than 10^-2
The questions are
1.What means boundary conditions for pair interaction?
2.How to model infinite film?
I'm not clear what you are asking. Your 2d system is periodic
in y, but not in x. PBC in LAMMPS means what it means in every MD
textbook. If 2 particles are at opposite y-ends of the box, they
interact thru the boundary with their images.
Steve
Dear Steve, thank you for reply.
My question really came from my bad education in MD.
However,
Is it a way to model an infinite film in LAMMPS? Should i use kspace_style command or there is another possibility?
My question really came from my bad education in MD.
However,
Is it a way to model an infinite film in LAMMPS?
Yes: Using periodic boundary conditions. Honestly, you should really
read some basic MD textbook *before* you try to use a MD code like
LAMMPS. You will save yourself a lot of time, and your chances to get
relevant results at the end will improve.
Should i use kspace_style command or there is another possibility?
Once again you can read in standard textbooks on the different methods
to tackle coulomb interactions with PBC, especially on the
difficulties that arise when the system is only periodic in 2
dimensions.
Best,
Laurent
I'll just add that the kspace command in LAMMPS normally
does fully periodic systems. But there is a "slab" option
for systems that are periodic in only 2 out of 3 dimensions.
Steve