Region command using type group

Dear,
I’m doing graphene and liquid simulations. Is it possible to apply the region command using the style block only to a group, for example only to the carbon group?

No. What do you need this for?

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I need to do a calculation in which the edges of the graphene will be fixed to both edges.

Using:
region left block INF INF INF -110 INF INF
region right block INF INF 304 INF INF INF

However, when including a gas or liquid in the system there is a problem with using these fixed regions. However, when including a gas or liquid in the system there is a problem with using these fixed regions. Because the liquid molecules can go in this region.

What is a “fixed region”?

Please note that that the term “fix” has a very specific meaning in the context of LAMMPS and thus is best avoided for describing anything that is not a fix style.

You still didn’t really answer my question and explained how you will use those regions in your LAMMPS input?

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What is a “fixed region”?

are the edges of the graphene sheet. I need to keep the edges fixed as I will pull the right edge.

region left block INF INF INF -110 INF INF
region right block INF INF 304 INF INF IN

You still have not not explained what you are doing (with the graphene) and from the context it seems that you want to immobilize those atoms (to fix has multiple meaning in english and - as I already mentioned - the term “fix” is best avoided when talking about LAMMPS as it is too easily confused with “applying a fix (command)”).

To immobilize atoms you either need to use fix setforce on those atoms or apply your time integration to all other atoms. In both cases the atoms this is being applied to have to be in a group (not region). Now you can define a group from a region, but you can also define a group from the atom type and if you want a group that covers the atoms from both subsets you can define a group that is an intersection of two groups. Please see the group command documentation for more inspiration.

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