I want to apply compressive hydrostatic pressure on a polymer melt using fix npt command. I want to know whether +ve values are compressive or negative values?
fix 1 water npt temp 300.0 300.0 100.0 iso 10.0 10.0 1000.0
like in command above, Pstart=10 and Pstop=10. Here does it mean compressive pressure?