Hi all,
I am currently running a simulation involving two separate platinum walls on the top and the bottom. By defining the initial volume in x, y, z direction, I was hoping they would have the exact same number of layers of molecules by assigning the same dimension. However, it appears that the upper wall of platinum has one less layer than the bottom wall of platinum. They are both close to the boundaries but not exceeding the boundaries. Why is there such mismatch even though the dimensions are the same?
With or without periodic boundaries? With periodic boundaries there is just one big wall.
First you talk of platinum atoms, now you talk of molecules. Which is it?
Most likely you defined your box boundaries exactly on the lattice points.
That creates an ambiguity with the atoms at the top and the bottom of the box.
Since you cannot have both of those sets of atoms, LAMMPS will remove one set, hence the mismatch.
If you either shift your lattice by a little bit, e.g. by adding origin 0.1 0.1 0.1 or you shift your box boundaries by a little bit, that ambiguity is removed and you’ll have the same number of atoms on both sides.
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