Density for solids in LAMMPS

Hi!
Maybe this is a dumb question, but I need to clarify if the density obtained from Lamms when analyzing solid structures is considered a bulk density instead of a skeleton density(the mass of the unit cell divided by the unit cell volume minus the free volume).

Thank you!

The density computed by LAMMPS that is available as a keyword with thermo_style custom is simply the sum of all atom masses divided by the volume of the entire simulation cell.

How to interpret that depends on how you define your system.