[lammps-users] Default phase and pressure in MD simulations


I’m trying to understand what is the default phase in MD simulation, is it air or vacuum? Can we compare the results of the simulation with experimental results performed in air?

What is the default pressure, is it 1 atm? I know instantaneous pressure in simulations doesn’t make sense, but there needs to be an average pressure of the system right? How do I find that? My pressure values seem very high (10^19, with real style units) to make any real meaning…and I am not applying any external pressure.