question about how to displace atoms one at a time

I want to displace in turn each atom in a cell and do a calculation.

displace_atoms is based on group-ids.

If I were to define a series of groups and put one atom in a group and then work
through each group in turn, that is OK in principle but there are only 32 total groups
allowed (including all). So if I have more than 31 atoms that won’t work.

Also, I don’t see an “un-group” command that would undo a group to make it reusable.

So what is the best way to sequentially displace each atom in the cell?

Best,
MSD

There is a group style delete that removes a group (and the group is no longer counted in the 32).

-Eric

I want to displace in turn each atom in a cell and do a calculation.

displace_atoms is based on group-ids.

If I were to define a series of groups and put one atom in a group and then work
through each group in turn, that is OK in principle but there are only 32 total groups
allowed (including all). So if I have more than 31 atoms that won’t work.

Also, I don’t see an “un-group” command that would undo a group to make it reusable.

there is. you can do “group delete”
first option of the list of available options in the documentation for the group command.

axel.

I want to displace in turn each atom in a cell and do a calculation.

displace_atoms is based on group-ids.

…and you can also use atom-style variables to define the per-atom displacements.
(re-)define the variable to have all unwanted atoms displaced by 0.0 0.0 0.0
and you don’t need groups at all. in fact, this can be set up to use equal style variables to select atom id and displacement, and you only have to redefine those.

axel.