Creating a Square Molecule


I want to create a square shape molecule in LAMMPS. The shape of the molecule is defined in a different file. For calling it in the script I have written the following code:

Pour 2d granular particles into container

dimension 2

lattice sq 0.95
atom_style sphere
boundary f fm p
newton off
comm_modify vel yes cutoff 2.5

fix prop all property/atom mol ghost yes

region reg block 0 100 0 50 -0.5 0.5 units box
create_box 1 reg

molecule object molecule.vshape
create_atoms 1 single 10 40 0 mol object 45677

But the error in the cmd is : ERROR: Invalid atom type in create_atoms mol command

May I know how to deal with this problem? I am attaching a picture of the molecule. Thank you.

Yeasir Mohammad Akib
MS Student

Please carefully re-read the documentation of the create_atoms command — LAMMPS documentation and pay special attention to all notes and comments where it mentions a different behavior when creating molecules instead of atoms.