Selection of Random Atom ID

Dear lammps users,

I am working on Monte Carlo relaxation of interface structure.

Is there some way to select random atom – ID in certain group?

Thanks in advance.

Jason.

There is a random function in the variable command - see its doc
page. If your group has a range of atom IDs, you could use it
in a formula to select an ID. I’m assuming you are asking how
to do this in an input script.

Paul (CCd) can also tell you about an extension he is making

to the fix gcmc command to do MC swaps of atoms types,
e.g. to relax an interface. I think he’s nearly ready to release it.

Steve

As Steve mentioned, I’ve been working on a new fix “atom swap” that will allow users to swap two atoms of different type according to standard MC rules. We’re still in testing phase for the new code, but I could send you a “beta” version for friendly user testing if you’d like. I anticipate we’ll release it for general use in early December.

Paul

Thanks for your help.

Grouped atom IDs are distributed sparsely in data file, so I filtered it by using if command when random IDs are selected.

Jason

Thanks for information.

I am working on relaxation of interface (grain boundary) with fixed atom number.

So I thought that fix gcmc cannot be applied to my work. ( I have tried to modify MC relaxation in lammps example directory)

Is there some way to relax this structure using gcmc without including ideal gas reservoir?

Jason

Thanks for information.

I am working on relaxation of interface (grain boundary) with fixed atom number.

So I thought that fix gcmc cannot be applied to my work. ( I have tried to modify MC relaxation in lammps example directory)

Is there some way to relax this structure using gcmc without including ideal gas reservoir?

Jason