Default pressure and phase in MD simulation


Im trying to understand what is the default phase in MD simulation, is it air or vacuum? What is the default pressure is it 1 atm? I know instantaneous pressure in simulations dont 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 to make any real meaning…and I am not applying any external pressure .

There is no “default” that is applicable to all simulations.

What is “normal” is something that you choose: with your geometry, with your boundary conditions, with for parameters, with your pair/bond/angle/etc styles and topology, with your choice of temperature and time integration, with your other choices that impact the forces in the system.

… then probably there is something wrong with how your have chosen to set up your system.