changing potential and number of atom type involved simulation

Dear lammps experts,
I created a Cu-bicrystal sample with a Sigma5 boundary and wrote a restart file. While creating the bicrystal, the potential I used was “Cu_mishin1.eam.alloy” and also the number of atom type was specified as 1.

Now, I am trying to segregate 1% of Zr-atoms in the boundary. I want to use new potential “CuZr_mm.eam.fs” and also change the number of atom type to 2.

Could you please suggest me how can I change the potential and number of atom type so that I can start my simulation using the restart file.

Thank you.

Dear lammps experts,
I created a Cu-bicrystal sample with a Sigma5 boundary and wrote a restart
file. While creating the bicrystal, the potential I used was
"Cu_mishin1.eam.alloy" and also the number of atom type was specified as 1.

Now, I am trying to segregate 1% of Zr-atoms in the boundary. I want to
use new potential "CuZr_mm.eam.fs" and also change the number of atom type
to 2.

Could you please suggest me how can I change the potential and number of
atom type so that I can start my simulation using the restart file.

​you cannot. the number of atom types is locked in. you have to convert
your restart into a data file, and then either manually edit it, or reserve
space for an additional atom type.
changing the pair style is always possible and so is updating the
pair_coeff settings. but wouldn't it be more consistent, to immediately
start with CuZr_mm.eam.fs? the fact, that it contains parameters for two
elements, does not require that you have two types of atoms in your system.

axel.