Bonds

Dear Lammps users,
I have a question about considering bonds in simulations. When do we need to consider and specify bond status in our simulations? I see bonds-related commands in some simulations, while there is a lack of them in some of them.

Best regards,

With classical force fields, bonds can be specified to creates molecules from 2 or more atoms. If a simulation does not have molecule, there is no need to define bond.

With reactive force fields (bond order-based force fields), bonds are never explicitly specified, they form and break based on the relative positions of the atoms.

Simon