How to assign values to specific group of atoms

Hi Axel,

please always copy the mailing list on your replies.

I want to define a variable called "partial enthalpy" to every atom. I have
a mixture system which includes two kind of atoms. I have obtained partial
enthalpies for each component in a separate simulation and now I need to use
those values in my main simulation. I looked up "set" command, but that is

how are you going to "use" those values, when LAMMPS
doesn't have such a property in the first place?

not for a new variable(here, I need to define partial enthalpy for each
atom).

axel.

That is why I want to define a vector variable (partial enthalpy). I need to use this vector variable in another compute command which will compute a new vector for all atoms. I have two groups of atoms and two numbers (partial enthalpies) that should be assigned to all atoms in each group. In the case that there exists just one kind of atoms a variable can be defined and all atoms can get a number but in this case that there exists two groups of atoms which I need to give all atoms in the same group a number there is no option in variable command.

I hope I could explain my problem.

Thanks,

That is why I want to define a vector variable (partial enthalpy). I need to
use this vector variable in another compute command which will compute a new
vector for all atoms. I have two groups of atoms and two numbers (partial
enthalpies) that should be assigned to all atoms in each group. In the case
that there exists just one kind of atoms a variable can be defined and all
atoms can get a number but in this case that there exists two groups of
atoms which I need to give all atoms in the same group a number there is no
option in variable command.

how about using an atom style that has par atom properties, that you don't need?
e.g. you can use atom style charge instead of atomic, so that even if you don't
use charges you can assign your property to the charge value.

axel.

If you're going to write your own compute, then the compute
allocates storage for a per-atom vector. If that vector
needs to persist from timestep to timestep (e.g. store the
old value until a new one is compute), then the compute can
use a fix store/state to do this. See the compute msd command
for an example that does this.

Steve